diff --git a/libs/timecode/src/time.cc b/libs/timecode/src/time.cc
index 7e8b94c121..b993c3eba0 100644
--- a/libs/timecode/src/time.cc
+++ b/libs/timecode/src/time.cc
@@ -609,7 +609,7 @@ timecode_to_sample(
 		bool use_offset, bool use_subframes,
     /* Note - framerate info is taken from Timecode::Time& */
 		double sample_frame_rate /**< may include pull up/down */,
-		int32_t subframes_per_frame,
+		uint32_t subframes_per_frame,
     /* optional offset  - can be improved: function pointer to lazily query this*/
 		bool offset_is_negative, int64_t offset_samples
 		)
@@ -711,7 +711,7 @@ sample_to_timecode (
 		double timecode_frames_per_second,
 		bool   timecode_drop_frames,
 		double sample_frame_rate/**< can include pull up/down */,
-		int32_t subframes_per_frame,
+		uint32_t subframes_per_frame,
     /* optional offset  - can be improved: function pointer to lazily query this*/
 		bool offset_is_negative, int64_t offset_samples
 		)
diff --git a/libs/timecode/timecode/time.h b/libs/timecode/timecode/time.h
index d9b3f01444..b1d34eebb8 100644
--- a/libs/timecode/timecode/time.h
+++ b/libs/timecode/timecode/time.h
@@ -116,7 +116,7 @@ timecode_to_sample(
 		bool use_offset, bool use_subframes,
     /* Note - framerate info is taken from Timecode::Time& */
 		double sample_frame_rate /**< may include pull up/down */,
-		int32_t subframes_per_frame /**< must not be 0 if use_subframes==true */,
+		uint32_t subframes_per_frame /**< must not be 0 if use_subframes==true */,
     /* optional offset  - can be improved: function pointer to lazily query this*/
 		bool offset_is_negative, int64_t offset_samples
 		);
@@ -128,7 +128,7 @@ void sample_to_timecode (
 		double timecode_frames_per_second,
 		bool   timecode_drop_frames,
 		double sample_frame_rate/**< can include pull up/down */,
-		int32_t subframes_per_frame,
+		uint32_t subframes_per_frame,
     /* optional offset  - can be improved: function pointer to lazily query this*/
 		bool offset_is_negative, int64_t offset_samples
 		);