diff --git a/src/arch/dotproductsse.h b/src/arch/dotproductsse.h
index 941c958fd2..522f8dd558 100644
--- a/src/arch/dotproductsse.h
+++ b/src/arch/dotproductsse.h
@@ -19,6 +19,8 @@
 #ifndef TESSERACT_ARCH_DOTPRODUCTSSE_H_
 #define TESSERACT_ARCH_DOTPRODUCTSSE_H_
 
+#include <cstdint>      // for int32_t
+
 namespace tesseract {
 
 // Computes and returns the dot product of the n-vectors u and v.