diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 01e1238e..5e7cc5a7 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -299,6 +299,8 @@ endif()
 if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
     target_compile_definitions(dynarmic PRIVATE FMT_USE_WINDOWS_H=0)
 endif()
+# Disable this as it relies on a non-standard feature
+target_compile_definitions(dynarmic PRIVATE FMT_USE_USER_DEFINED_LITERALS=0)
 
 export(
     TARGETS   dynarmic boost fmt xbyak
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index a4d7c044..b53e262d 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -41,9 +41,11 @@ create_target_directory_groups(dynarmic_print_info)
 target_link_libraries(dynarmic_tests PRIVATE dynarmic boost catch fmt xbyak)
 target_include_directories(dynarmic_tests PRIVATE . ../src)
 target_compile_options(dynarmic_tests PRIVATE ${DYNARMIC_CXX_FLAGS})
+target_compile_definitions(dynarmic_tests PRIVATE FMT_USE_USER_DEFINED_LITERALS=0)
 
 target_link_libraries(dynarmic_print_info PRIVATE dynarmic boost catch fmt)
 target_include_directories(dynarmic_print_info PRIVATE . ../src)
 target_compile_options(dynarmic_print_info PRIVATE ${DYNARMIC_CXX_FLAGS})
+target_compile_definitions(dynarmic_print_info PRIVATE FMT_USE_USER_DEFINED_LITERALS=0)
 
 add_test(dynarmic_tests dynarmic_tests)