diff --git a/src/libImaging/ImPlatform.h b/src/libImaging/ImPlatform.h
index 6f9ee067f..90d87e445 100644
--- a/src/libImaging/ImPlatform.h
+++ b/src/libImaging/ImPlatform.h
@@ -9,9 +9,11 @@
 
 #include "Python.h"
 
-#include <emmintrin.h>
-#include <mmintrin.h>
-#include <smmintrin.h>
+#if defined(__SSE4_2__)
+    #include <emmintrin.h>
+    #include <mmintrin.h>
+    #include <smmintrin.h>
+#endif
 #if defined(__AVX2__)
     #include <immintrin.h>
 #endif
diff --git a/src/libImaging/ImagingUtils.h b/src/libImaging/ImagingUtils.h
index e9d2f894f..8357719b5 100644
--- a/src/libImaging/ImagingUtils.h
+++ b/src/libImaging/ImagingUtils.h
@@ -42,13 +42,15 @@ static float inline _i2f(int v) { return (float)v; }
 #endif
 
 
-__m128i inline
+#if defined(__SSE4_2__)
+static __m128i inline
 mm_cvtepu8_epi32(void *ptr) {
     return _mm_cvtepu8_epi32(_mm_cvtsi32_si128(*(INT32 *) ptr));
 }
+#endif
 
 #if defined(__AVX2__)
-__m256i inline
+static __m256i inline
 mm256_cvtepu8_epi32(void *ptr) {
     return _mm256_cvtepu8_epi32(_mm_cvtsi64_si128(*(int64_t *) ptr));
 }