diff --git a/src/subcommand/inject_main.cpp b/src/subcommand/inject_main.cpp
index a9ed8cbcb8f..99b1c8fe234 100644
--- a/src/subcommand/inject_main.cpp
+++ b/src/subcommand/inject_main.cpp
@@ -14,6 +14,7 @@
 #include "../alignment.hpp"
 #include "../vg.hpp"
 #include "../xg.hpp"
+#include "../hts_alignment_emitter.hpp"
 #include <vg/io/stream.hpp>
 #include <vg/io/vpkg.hpp>
 #include <bdsg/overlays/overlay_helper.hpp>
@@ -23,10 +24,11 @@ using namespace vg;
 using namespace vg::subcommand;
 
 void help_inject(char** argv) {
-    cerr << "usage: " << argv[0] << " inject [options] input.[bam|sam|cram] >output.gam" << endl
+    cerr << "usage: " << argv[0] << " inject -x graph.xg [options] input.[bam|sam|cram] >output.gam" << endl
          << endl
          << "options:" << endl
          << "    -x, --xg-name FILE       use this graph or xg index (required, non-XG formats also accepted)" << endl
+         << "    -o, --output-format NAME output the alignments in NAME format (gam / gaf / json) [gam]" << endl
          << "    -t, --threads N          number of threads to use" << endl;
 }
 
@@ -37,6 +39,8 @@ int main_inject(int argc, char** argv) {
     }
 
     string xg_name;
+    string output_format = "GAM";
+    std::set<std::string> output_formats = { "GAM", "GAF", "JSON" };
     int threads = get_thread_count();
 
     int c;
@@ -46,12 +50,13 @@ int main_inject(int argc, char** argv) {
         {
           {"help", no_argument, 0, 'h'},
           {"xg-name", required_argument, 0, 'x'},
+          {"output-format", required_argument, 0, 'o'},
           {"threads", required_argument, 0, 't'},
           {0, 0, 0, 0}
         };
 
         int option_index = 0;
-        c = getopt_long (argc, argv, "hx:t:",
+        c = getopt_long (argc, argv, "hx:o:t:",
                          long_options, &option_index);
 
         // Detect the end of the options.
@@ -63,6 +68,19 @@ int main_inject(int argc, char** argv) {
         case 'x':
             xg_name = optarg;
             break;
+        
+        case 'o':
+            {
+                output_format = optarg;
+                for (char& c : output_format) {
+                    c = std::toupper(c);
+                }
+                if (output_formats.find(output_format) == output_formats.end()) {
+                    std::cerr << "error: [vg inject] Invalid output format: " << optarg << std::endl;
+                    std::exit(1);
+                }
+            }
+            break;
 
         case 't':
           threads = parse<int>(optarg);
@@ -90,14 +108,14 @@ int main_inject(int argc, char** argv) {
     }
     unique_ptr<PathHandleGraph> path_handle_graph = vg::io::VPKG::load_one<PathHandleGraph>(xg_name);
     bdsg::PathPositionOverlayHelper overlay_helper;
-    PathPositionHandleGraph* xgidx = overlay_helper.apply(path_handle_graph.get());    
+    PathPositionHandleGraph* xgidx = overlay_helper.apply(path_handle_graph.get());
 
-    vg::io::ProtobufEmitter<Alignment> buf(cout);
-    function<void(Alignment&)> lambda = [&buf](Alignment& aln) {
-#pragma omp critical (buf)
-        {
-            buf.write(std::move(aln));
-        }
+    // We don't do HTS output formats but we do need an empty paths collection to make an alignment emitter
+    vector<tuple<path_handle_t, size_t, size_t>> paths;
+    unique_ptr<vg::io::AlignmentEmitter> alignment_emitter = get_alignment_emitter("-", output_format, paths, threads, xgidx);
+
+    function<void(Alignment&)> lambda = [&](Alignment& aln) {
+        alignment_emitter->emit_mapped_single({std::move(aln)});
     };
     if (threads > 1) {
         hts_for_each_parallel(file_name, lambda, xgidx);
diff --git a/test/t/39_vg_inject.t b/test/t/39_vg_inject.t
index 541c2e9cbf6..f1aa362cee1 100644
--- a/test/t/39_vg_inject.t
+++ b/test/t/39_vg_inject.t
@@ -6,7 +6,7 @@ BASH_TAP_ROOT=../deps/bash-tap
 PATH=../bin:$PATH # for vg
 
 
-plan tests 12
+plan tests 13
 
 vg construct -r small/x.fa > j.vg
 vg index -x j.xg j.vg
@@ -52,5 +52,7 @@ cat <(samtools view -H small/x.bam) <(printf "name\t4\t*\t0\t0\t*\t*\t0\t0\tACGT
 is "$(vg inject -x x.xg unmapped.sam | vg view -aj - | grep "path" | wc -l)" 0 "vg inject does not make an alignment for an umapped read"
 is "$(echo $?)" 0 "vg inject does not crash on an unmapped read"
 
+is $(vg inject -x x.xg small/x.bam -o GAF | wc -l) \
+    1000 "vg inject supports GAF output"
 
 rm j.vg j.xg x.vg x.gcsa x.gcsa.lcp x.xg unmapped.sam