diff --git a/icu4c/source/i18n/messageformat2_allocation.h b/icu4c/source/i18n/messageformat2_allocation.h
index a0d4d1db513c..431862cecef5 100644
--- a/icu4c/source/i18n/messageformat2_allocation.h
+++ b/icu4c/source/i18n/messageformat2_allocation.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_UTILS_H
diff --git a/icu4c/source/i18n/messageformat2_cached_formatters.h b/icu4c/source/i18n/messageformat2_cached_formatters.h
index 33b24d07648a..455f7de7ad33 100644
--- a/icu4c/source/i18n/messageformat2_cached_formatters.h
+++ b/icu4c/source/i18n/messageformat2_cached_formatters.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_CACHED_FORMATTERS_H
diff --git a/icu4c/source/i18n/messageformat2_checker.h b/icu4c/source/i18n/messageformat2_checker.h
index 38de91c3756c..4bb0498efb99 100644
--- a/icu4c/source/i18n/messageformat2_checker.h
+++ b/icu4c/source/i18n/messageformat2_checker.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT_CHECKER_H
diff --git a/icu4c/source/i18n/messageformat2_errors.h b/icu4c/source/i18n/messageformat2_errors.h
index 522adc1be86e..ef2ad20faddb 100644
--- a/icu4c/source/i18n/messageformat2_errors.h
+++ b/icu4c/source/i18n/messageformat2_errors.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_ERRORS_H
@@ -18,7 +20,6 @@
 #if !UCONFIG_NO_MF2
 
 #include "unicode/messageformat2_data_model_names.h"
-#include "unicode/utypes.h"
 #include "unicode/unistr.h"
 
 #include "uvector.h"
diff --git a/icu4c/source/i18n/messageformat2_evaluation.h b/icu4c/source/i18n/messageformat2_evaluation.h
index e9ecb23c2568..b8ae0242367d 100644
--- a/icu4c/source/i18n/messageformat2_evaluation.h
+++ b/icu4c/source/i18n/messageformat2_evaluation.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_EVALUATION_H
diff --git a/icu4c/source/i18n/messageformat2_function_registry_internal.h b/icu4c/source/i18n/messageformat2_function_registry_internal.h
index 72ef17ceda7f..b34cb9b01421 100644
--- a/icu4c/source/i18n/messageformat2_function_registry_internal.h
+++ b/icu4c/source/i18n/messageformat2_function_registry_internal.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_FUNCTION_REGISTRY_INTERNAL_H
diff --git a/icu4c/source/i18n/messageformat2_macros.h b/icu4c/source/i18n/messageformat2_macros.h
index 8efa45432f5c..ee8cf0779e6b 100644
--- a/icu4c/source/i18n/messageformat2_macros.h
+++ b/icu4c/source/i18n/messageformat2_macros.h
@@ -1,13 +1,13 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT2_MACROS_H
 #define MESSAGEFORMAT2_MACROS_H
 
-#include "unicode/utypes.h"
-
 #if U_SHOW_CPLUSPLUS_API
 
 #if !UCONFIG_NO_FORMATTING
diff --git a/icu4c/source/i18n/messageformat2_parser.h b/icu4c/source/i18n/messageformat2_parser.h
index 3dc45e19a9a7..81a81abf6fa6 100644
--- a/icu4c/source/i18n/messageformat2_parser.h
+++ b/icu4c/source/i18n/messageformat2_parser.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT_PARSER_H
diff --git a/icu4c/source/i18n/messageformat2_serializer.h b/icu4c/source/i18n/messageformat2_serializer.h
index d6c7eb5c47d7..4b72d1ca715f 100644
--- a/icu4c/source/i18n/messageformat2_serializer.h
+++ b/icu4c/source/i18n/messageformat2_serializer.h
@@ -1,6 +1,8 @@
 // © 2024 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
 
+#include "unicode/utypes.h"
+
 #ifndef U_HIDE_DEPRECATED_API
 
 #ifndef MESSAGEFORMAT_SERIALIZER_H
diff --git a/icu4c/source/test/intltest/messageformat2test_utils.h b/icu4c/source/test/intltest/messageformat2test_utils.h
index a26a07625707..add3992f4b7a 100644
--- a/icu4c/source/test/intltest/messageformat2test_utils.h
+++ b/icu4c/source/test/intltest/messageformat2test_utils.h
@@ -4,6 +4,8 @@
 #ifndef _TESTMESSAGEFORMAT2_UTILS
 #define _TESTMESSAGEFORMAT2_UTILS
 
+#include "unicode/utypes.h"
+
 #if !UCONFIG_NO_FORMATTING
 
 #if !UCONFIG_NO_MF2