diff --git a/c/detools.h b/c/detools.h
index 1cc9c6f..5c50b00 100644
--- a/c/detools.h
+++ b/c/detools.h
@@ -29,6 +29,10 @@
 #ifndef DETOOLS_H
 #define DETOOLS_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * Configuration.
  *
@@ -629,4 +633,8 @@ int detools_apply_patch_in_place_filenames(const char *memory_p,
  */
 const char *detools_error_as_string(int error);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/c/heatshrink/heatshrink_decoder.h b/c/heatshrink/heatshrink_decoder.h
index bda8399..63211e4 100644
--- a/c/heatshrink/heatshrink_decoder.h
+++ b/c/heatshrink/heatshrink_decoder.h
@@ -1,6 +1,10 @@
 #ifndef HEATSHRINK_DECODER_H
 #define HEATSHRINK_DECODER_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include <stdint.h>
 #include <stddef.h>
 #include "heatshrink_common.h"
@@ -97,4 +101,8 @@ HSD_poll_res heatshrink_decoder_poll(heatshrink_decoder *hsd,
  * call heatshrink_decoder_poll and repeat. */
 HSD_finish_res heatshrink_decoder_finish(heatshrink_decoder *hsd);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif