diff --git a/ffi/capi/bindings/c/DecomposingNormalizer.h b/ffi/capi/bindings/c/DecomposingNormalizer.h
index 79d528b4696..0b0dd43c418 100644
--- a/ffi/capi/bindings/c/DecomposingNormalizer.h
+++ b/ffi/capi/bindings/c/DecomposingNormalizer.h
@@ -29,11 +29,11 @@ icu4x_DecomposingNormalizer_create_nfkd_with_provider_mv1_result icu4x_Decomposi
 
 void icu4x_DecomposingNormalizer_normalize_mv1(const DecomposingNormalizer* self, DiplomatStringView s, DiplomatWrite* write);
 
-bool icu4x_DecomposingNormalizer_is_normalized_mv1(const DecomposingNormalizer* self, DiplomatStringView s);
+bool icu4x_DecomposingNormalizer_is_normalized_utf8_mv1(const DecomposingNormalizer* self, DiplomatStringView s);
 
 bool icu4x_DecomposingNormalizer_is_normalized_utf16_mv1(const DecomposingNormalizer* self, DiplomatString16View s);
 
-size_t icu4x_DecomposingNormalizer_is_normalized_up_to_mv1(const DecomposingNormalizer* self, DiplomatStringView s);
+size_t icu4x_DecomposingNormalizer_is_normalized_utf8_up_to_mv1(const DecomposingNormalizer* self, DiplomatStringView s);
 
 size_t icu4x_DecomposingNormalizer_is_normalized_utf16_up_to_mv1(const DecomposingNormalizer* self, DiplomatString16View s);
 
diff --git a/ffi/capi/bindings/cpp/icu4x/DecomposingNormalizer.hpp b/ffi/capi/bindings/cpp/icu4x/DecomposingNormalizer.hpp
index f9442d42bf6..c50faefae02 100644
--- a/ffi/capi/bindings/cpp/icu4x/DecomposingNormalizer.hpp
+++ b/ffi/capi/bindings/cpp/icu4x/DecomposingNormalizer.hpp
@@ -32,11 +32,11 @@ namespace capi {
 
     void icu4x_DecomposingNormalizer_normalize_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatStringView s, icu4x::diplomat::capi::DiplomatWrite* write);
 
-    bool icu4x_DecomposingNormalizer_is_normalized_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatStringView s);
+    bool icu4x_DecomposingNormalizer_is_normalized_utf8_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatStringView s);
 
     bool icu4x_DecomposingNormalizer_is_normalized_utf16_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatString16View s);
 
-    size_t icu4x_DecomposingNormalizer_is_normalized_up_to_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatStringView s);
+    size_t icu4x_DecomposingNormalizer_is_normalized_utf8_up_to_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatStringView s);
 
     size_t icu4x_DecomposingNormalizer_is_normalized_utf16_up_to_mv1(const icu4x::capi::DecomposingNormalizer* self, icu4x::diplomat::capi::DiplomatString16View s);
 
@@ -83,7 +83,7 @@ inline void icu4x::DecomposingNormalizer::normalize_write(std::string_view s, W&
 }
 
 inline bool icu4x::DecomposingNormalizer::is_normalized(std::string_view s) const {
-    auto result = icu4x::capi::icu4x_DecomposingNormalizer_is_normalized_mv1(this->AsFFI(),
+    auto result = icu4x::capi::icu4x_DecomposingNormalizer_is_normalized_utf8_mv1(this->AsFFI(),
         {s.data(), s.size()});
     return result;
 }
@@ -95,7 +95,7 @@ inline bool icu4x::DecomposingNormalizer::is_normalized16(std::u16string_view s)
 }
 
 inline size_t icu4x::DecomposingNormalizer::is_normalized_up_to(std::string_view s) const {
-    auto result = icu4x::capi::icu4x_DecomposingNormalizer_is_normalized_up_to_mv1(this->AsFFI(),
+    auto result = icu4x::capi::icu4x_DecomposingNormalizer_is_normalized_utf8_up_to_mv1(this->AsFFI(),
         {s.data(), s.size()});
     return result;
 }
diff --git a/ffi/capi/src/normalizer.rs b/ffi/capi/src/normalizer.rs
index b3a09822c84..ba79698a9e6 100644
--- a/ffi/capi/src/normalizer.rs
+++ b/ffi/capi/src/normalizer.rs
@@ -285,7 +285,7 @@ pub mod ffi {
         )]
         #[diplomat::attr(not(supports = utf8_strings), disable)]
         #[diplomat::attr(*, rename = "is_normalized")]
-        pub fn is_normalized(&self, s: &DiplomatStr) -> bool {
+        pub fn is_normalized_utf8(&self, s: &DiplomatStr) -> bool {
             self.0.as_borrowed().is_normalized_utf8(s)
         }
 
@@ -314,7 +314,7 @@ pub mod ffi {
         )]
         #[diplomat::attr(not(supports = utf8_strings), disable)]
         #[diplomat::attr(*, rename = "is_normalized_up_to")]
-        pub fn is_normalized_up_to(&self, s: &DiplomatStr) -> usize {
+        pub fn is_normalized_utf8_up_to(&self, s: &DiplomatStr) -> usize {
             self.0.as_borrowed().split_normalized_utf8(s).0.len()
         }