diff --git a/wdl2cwl/main.py b/wdl2cwl/main.py
index 290fa744..832fb9c4 100644
--- a/wdl2cwl/main.py
+++ b/wdl2cwl/main.py
@@ -722,7 +722,11 @@ def get_workflow_outputs(
             with WDLSourceLine(item.info, ConversionException):
                 output_name = item.name
                 item_expr = item.info.expr
-                output_source = item_expr.expr.name[::-1].replace(".", "/", 1)[::-1]
+                if isinstance(item_expr, WDL.Expr.Get):
+                    output_source = item_expr.expr.name[::-1].replace(".", "/", 1)[::-1]
+                else:
+                    output_source = f"$({self.get_expr(item_expr)})"
+
                 # replace just the last occurrence of a period with a slash
                 # by first reversing the string and the replace the first occurrence
                 # then reversing the result
@@ -1019,14 +1023,14 @@ def get_expr_get(self, wdl_get_expr: WDL.Expr.Get) -> str:
 
     def get_expr_ident(self, wdl_ident_expr: WDL.Expr.Ident) -> str:
         """Translate WDL Ident Expressions."""
-        id_name = wdl_ident_expr.name
+        id_name: str = wdl_ident_expr.name
         referee = wdl_ident_expr.referee
         optional = wdl_ident_expr.type.optional
         if referee:
             with WDLSourceLine(referee, ConversionException):
                 if isinstance(referee, WDL.Tree.Call):
                     return id_name
-                if referee.expr and (
+                if hasattr(referee, 'expr') and referee.expr is not None and (
                     wdl_ident_expr.name in self.optional_cwl_null
                     or wdl_ident_expr.name not in self.non_static_values
                 ):
diff --git a/wdl2cwl/tests/cwl_files/blast.cwl b/wdl2cwl/tests/cwl_files/blast.cwl
new file mode 100644
index 00000000..88f82107
--- /dev/null
+++ b/wdl2cwl/tests/cwl_files/blast.cwl
@@ -0,0 +1,217 @@
+cwlVersion: v1.2
+id: blast
+class: Workflow
+requirements:
+  - class: InlineJavascriptRequirement
+inputs:
+  - id: blast_docker_override
+    type:
+      - string
+      - 'null'
+  - id: blast_docker
+    type:
+      - string
+      - 'null'
+  - id: queryfa
+    type: File
+  - id: fname
+    default: /sfs/blastdb/2019_ncov/nucl/v6/ncov
+    type: string
+  - id: method
+    default: blastn
+    type: string
+  - id: outfmt
+    default: 7
+    type: int
+  - id: evalue
+    default: 10.0
+    type: float
+  - id: Outfile
+    type:
+      - string
+      - 'null'
+  - id: threads
+    default: 8
+    type: int
+  - id: runblastp.max_target_seqs
+    default: 100
+    type: int
+  - id: runblastp.word_size
+    default: 6
+    type: int
+  - id: runblastp.seg
+    default: no
+    type: string
+  - id: runblastp.comp_based_stats
+    default: '2'
+    type: string
+  - id: runblastp.matrix
+    default: BLOSUM62
+    type: string
+  - id: runblastp.gapopen
+    default: 11
+    type: int
+  - id: runblastp.gapextend
+    default: 1
+    type: int
+  - id: runblastp.max_hsps
+    type:
+      - int
+      - 'null'
+  - id: runblastp.taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastp.negative_taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastp.lcase_masking
+    default: false
+    type: boolean
+  - id: runblastn.max_target_seqs
+    default: 100
+    type: int
+  - id: runblastn.word_size
+    default: 28
+    type: int
+  - id: runblastn.reward
+    default: 1
+    type: int
+  - id: runblastn.penalty
+    default: -2
+    type: int
+  - id: runblastn.strand
+    default: both
+    type: string
+  - id: runblastn.gapopen
+    default: 0
+    type: int
+  - id: runblastn.gapextend
+    default: 0
+    type: int
+  - id: runblastn.dust
+    default: "'20 64 1'"
+    type: string
+  - id: runblastn.max_hsps
+    type:
+      - int
+      - 'null'
+  - id: runblastn.tasks
+    default: megablast
+    type: string
+  - id: runblastn.taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastn.negative_taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastn.lcase_masking
+    default: false
+    type: boolean
+  - id: runblastx.max_target_seqs
+    default: 100
+    type: int
+  - id: runblastx.word_size
+    default: 6
+    type: int
+  - id: runblastx.seg
+    default: "'12 2.2 2.5'"
+    type: string
+  - id: runblastx.comp_based_stats
+    default: '2'
+    type: string
+  - id: runblastx.matrix
+    default: BLOSUM62
+    type: string
+  - id: runblastx.gapopen
+    default: 11
+    type: int
+  - id: runblastx.gapextend
+    default: 1
+    type: int
+  - id: runblastx.taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastx.negative_taxids
+    type:
+      - string
+      - 'null'
+  - id: runblastx.max_hsps
+    type:
+      - int
+      - 'null'
+  - id: runblastx.lcase_masking
+    default: false
+    type: boolean
+  - id: runtblastn.max_target_seqs
+    default: 100
+    type: int
+  - id: runtblastn.word_size
+    default: 6
+    type: int
+  - id: runtblastn.seg
+    default: "'12 2.2 2.5'"
+    type: string
+  - id: runtblastn.comp_based_stats
+    default: '2'
+    type: string
+  - id: runtblastn.matrix
+    default: BLOSUM62
+    type: string
+  - id: runtblastn.gapopen
+    default: 11
+    type: int
+  - id: runtblastn.gapextend
+    default: 1
+    type: int
+  - id: runtblastn.lcase_masking
+    default: false
+    type: boolean
+  - id: runtblastn.max_hsps
+    type:
+      - int
+      - 'null'
+  - id: runtblastn.taxids
+    type:
+      - string
+      - 'null'
+  - id: runtblastn.negative_taxids
+    type:
+      - string
+      - 'null'
+  - id: runtblastx.taxids
+    type:
+      - string
+      - 'null'
+  - id: runtblastx.word_size
+    default: 3
+    type: int
+  - id: runtblastx.max_target_seqs
+    default: 100
+    type: int
+  - id: runtblastx.seg
+    default: "'12 2.2 2.5'"
+    type: string
+  - id: runtblastx.matrix
+    default: BLOSUM62
+    type: string
+  - id: runtblastx.lcase_masking
+    default: false
+    type: boolean
+  - id: runtblastx.negative_taxids
+    type:
+      - string
+      - 'null'
+  - id: runtblastx.max_hsps
+    type:
+      - int
+      - 'null'
+steps: []
+outputs:
+  - id: blast.fina_output
+    outputSource: '$([inputs["runtblastx.out"] === null '
+    type: File
diff --git a/wdl2cwl/tests/test_cwl.py b/wdl2cwl/tests/test_cwl.py
index 1e2b981b..742c18ea 100644
--- a/wdl2cwl/tests/test_cwl.py
+++ b/wdl2cwl/tests/test_cwl.py
@@ -68,6 +68,7 @@ def test_meta(caplog: pytest.LogCaptureFixture) -> None:
         ("vt.wdl"),
         ("whatshap.wdl"),
         ("workflow_inputs.wdl"),
+        ("blast.wdl"),
     ],
 )
 def test_wdls(description_name: str) -> None:
diff --git a/wdl2cwl/tests/wdl_files/blast.wdl b/wdl2cwl/tests/wdl_files/blast.wdl
new file mode 100644
index 00000000..450c1661
--- /dev/null
+++ b/wdl2cwl/tests/wdl_files/blast.wdl
@@ -0,0 +1,325 @@
+version 1.0
+
+workflow blast {
+  input {
+    String? blast_docker_override
+    String  blast_docker= select_first([blast_docker_override,"swr.cn-south-1.myhuaweicloud.com/cngbdb/blast:1.2"])
+    File    queryfa
+    String  fname       = '/sfs/blastdb/2019_ncov/nucl/v6/ncov'
+    String  method      = 'blastn'
+    Int     outfmt      = 7
+    Float   evalue      = 10
+    String  Outfile     = basename(queryfa)+'.blast_result.txt'
+    Int     threads     = 8
+  }
+  if (method == 'blastp') {
+    call runblastp{
+      input:
+        Fname      = fname,
+        Queryfa    = queryfa,
+        docker     = blast_docker,
+        outfmt     = outfmt,
+        evalue     = evalue,
+        Outfile    = Outfile,
+        threads    = threads
+    }
+  }
+  if ( method == 'blastn'){
+    call runblastn{
+      input:
+        Fname      = fname,
+        Queryfa    = queryfa,
+        docker     = blast_docker,
+        outfmt     = outfmt,
+        evalue     = evalue,
+        Outfile    = Outfile,
+        threads    = threads
+    }
+  }
+  if ( method == 'blastx'){
+    call runblastx{
+      input:
+        Fname      = fname,
+        Queryfa    = queryfa,
+        docker     = blast_docker,
+        outfmt     = outfmt,
+        evalue     = evalue,
+        Outfile    = Outfile,
+        threads    = threads
+    }
+  }
+  if ( method == 'queryfa'){
+    call runtblastn{
+      input:
+        Fname      = fname,
+        Queryfa    = queryfa,
+        docker     = blast_docker,
+        outfmt     = outfmt,
+        evalue     = evalue,
+        Outfile    = Outfile,
+        threads    = threads
+    }
+  }
+  if ( method == 'tblastx'){
+    call runtblastx{
+      input:
+        Fname      = fname,
+        Queryfa    = queryfa,
+        docker     = blast_docker,
+        outfmt     = outfmt,
+        evalue     = evalue,
+        Outfile    = Outfile,
+        threads    = threads
+    }
+  }
+  output {
+    File fina_output =select_first([runtblastx.out,runblastp.out,runblastn.out,runblastx.out,runtblastn.out])
+  }
+}
+
+task runblastn {
+  input {
+    String  docker
+    File    Queryfa
+    String  Fname
+    String  Outfile
+    Int threads
+    #blast optional
+    Int     outfmt
+    Int     max_target_seqs = 100
+    Float   evalue
+    Int     word_size       = 28
+    Int     reward          = 1
+    Int     penalty         = -2
+    String  strand          = 'both'
+    Int     gapopen         = 0
+    Int     gapextend       = 0
+    String  dust            = "'20 64 1'"
+    Int?    max_hsps
+    String  tasks           = "megablast"
+    String?   taxids
+    String? negative_taxids
+    Boolean lcase_masking   = false
+  }
+  runtime{
+    docker : docker
+    cpu    : "8"
+    memory : "16G"
+  }
+  command {
+    set -e
+    blastn -db "${Fname}" \
+    -show_gis \
+    -query ${Queryfa} \
+    -outfmt ${outfmt} \
+    -out     ${Outfile} \
+    -max_target_seqs ${max_target_seqs} \
+    -evalue ${evalue} \
+    -word_size ${word_size} \
+    -penalty ${penalty} \
+    -reward  ${reward} \
+    -dust ${dust} \
+    -gapopen ${gapopen} \
+    -gapextend ${gapextend} \
+    -task ${tasks} \
+    -strand  ${strand} \
+    -num_threads ${threads} \
+    ${true='-lcase_masking' false='' lcase_masking} ${"-max_hsps "+max_hsps} ${"-taxids " +taxids} ${"-negative_taxids " +negative_taxids}\
+
+  }
+  output {
+    File out = "${Outfile}"
+  }
+}
+
+task runblastp {
+  input {
+    String  docker
+    File    Queryfa
+    String  Fname
+    #blast optional
+    Int     outfmt
+    String  Outfile
+    Float   evalue
+    Int threads
+    Int     max_target_seqs  = 100
+    Int     word_size        = 6
+    String seg               = "no"
+    String comp_based_stats  = "2"
+    String matrix            = "BLOSUM62"
+    Int     gapopen          = 11
+    Int     gapextend        = 1
+    Int?    max_hsps
+    String?   taxids
+    String? negative_taxids
+    Boolean lcase_masking    = false
+  }
+  runtime{
+    docker : docker
+    cpu    : "8"
+    memory : "16G"
+  }
+  command {
+    set -e
+    blastp -db "${Fname}" \
+    -query ${Queryfa} \
+    -outfmt ${outfmt} \
+    -out     ${Outfile} \
+    -max_target_seqs ${max_target_seqs} \
+    -comp_based_stats ${comp_based_stats} \
+    -evalue ${evalue} \
+    -word_size ${word_size} \
+    -matrix   ${matrix} \
+    -seg     ${seg} \
+    -gapopen ${gapopen} \
+    -gapextend ${gapextend} \
+    -num_threads ${threads} \
+    ${true='-lcase_masking' false='' lcase_masking} ${"-max_hsps "+max_hsps} ${"-taxids " +taxids} ${"-negative_taxids " +negative_taxids} \
+
+  }
+  output {
+    File out = "${Outfile}"
+  }
+}
+
+task runblastx {
+  input {
+    File   Queryfa
+    String Fname
+    Int    outfmt
+    Float  evalue
+    String Outfile
+    String docker
+    Int     threads
+    Int    max_target_seqs  =  100
+    Int    word_size        =  6
+    String seg              =  "'12 2.2 2.5'"
+    String comp_based_stats =  "2"
+    String matrix           =  "BLOSUM62"
+    Int    gapopen          =  11
+    Int    gapextend        =  1
+    String?   taxids
+    String? negative_taxids
+    Int?    max_hsps
+    Boolean lcase_masking    = false
+  }
+  runtime{
+    docker : docker
+    cpu   : "8"
+    memory : "16G"
+  }
+  command {
+    set -e
+    blastx -db "${Fname}" \
+    -query ${Queryfa} \
+    -outfmt ${outfmt} \
+    -out     ${Outfile} \
+    -max_target_seqs ${max_target_seqs} \
+    -comp_based_stats ${comp_based_stats} \
+    -evalue ${evalue} \
+    -word_size ${word_size} \
+    -matrix   ${matrix} \
+    -seg     ${seg} \
+    -gapopen ${gapopen} \
+    -gapextend ${gapextend} \
+    -num_threads ${threads} \
+    ${true='-lcase_masking' false='' lcase_masking} ${"-max_hsps "+max_hsps} ${"-taxids " +taxids} ${"-negative_taxids " +negative_taxids}\
+
+  }
+  output {
+    File out = "$${Outfile}"
+  }
+}
+
+task runtblastn {
+  input {
+    File   Queryfa
+    String Fname
+    Int    outfmt
+    Float  evalue
+    String Outfile
+    String docker
+    Int    threads
+    Int    max_target_seqs  = 100
+    Int    word_size        = 6
+    String seg              = "'12 2.2 2.5'"
+    String comp_based_stats = "2"
+    String matrix           = "BLOSUM62"
+    Int    gapopen          = 11
+    Int    gapextend        = 1
+    Boolean lcase_masking   = false
+    Int?    max_hsps
+    String?   taxids
+    String? negative_taxids
+  }
+  runtime{
+    docker :docker
+    cpu    : "8"
+    memory : "16G"
+  }
+  command {
+    set -e
+    tblastn -db "${Fname}" \
+    -query ${Queryfa} \
+    -outfmt ${outfmt} \
+    -out    ${Outfile} \
+    -max_target_seqs ${max_target_seqs} \
+    -comp_based_stats ${comp_based_stats} \
+    -evalue ${evalue} \
+    -word_size ${word_size} \
+    -matrix   ${matrix} \
+    -seg     ${seg} \
+    -gapopen ${gapopen} \
+    -gapextend ${gapextend} \
+    -num_threads ${threads} \
+    ${true='-lcase_masking' false='' lcase_masking} ${"-max_hsps "+max_hsps} ${"-taxids " +taxids} ${"-negative_taxids " +negative_taxids}\
+
+  }
+  output {
+    File out = "${Outfile}"
+  }
+}
+
+task runtblastx {
+  input {
+    File   Queryfa
+    String Fname
+    Int    outfmt
+    String Outfile
+    Int threads
+    Float  evalue
+    String docker
+    String?   taxids
+    Int    word_size        = 3
+    Int    max_target_seqs  = 100
+    String seg              = "'12 2.2 2.5'"
+    String matrix           = "BLOSUM62"
+    Boolean lcase_masking   = false
+    String? negative_taxids
+    Int?    max_hsps
+  }
+  runtime{
+    docker :docker
+    cpu    : "8"
+    memory : "16G"
+  }
+  command {
+    set -e
+    tblastx -db "${Fname}" \
+    -query ${Queryfa} \
+    -outfmt ${outfmt} \
+    -out     ${Outfile} \
+    -max_target_seqs ${max_target_seqs} \
+    -evalue ${evalue} \
+    -word_size ${word_size} \
+    -matrix   ${matrix} \
+    -seg     ${seg} \
+    -num_threads ${threads} \
+    ${true='-lcase_masking' false='' lcase_masking} ${"-max_hsps "+max_hsps} ${"-taxids " +taxids} ${"-negative_taxids " +negative_taxids}\
+  }
+  output {
+    File out = "${Outfile}"
+  }
+}
+
+