diff --git a/jdhuff.c b/jdhuff.c
index c2b38a9e..f822dba8 100644
--- a/jdhuff.c
+++ b/jdhuff.c
@@ -758,7 +758,7 @@ decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
     usefast = 0;
   }
 
-  if (cinfo->src->bytes_in_buffer < BUFSIZE * cinfo->blocks_in_MCU
+  if (cinfo->src->bytes_in_buffer < BUFSIZE * (size_t)cinfo->blocks_in_MCU
     || cinfo->unread_marker != 0)
     usefast = 0;
 
diff --git a/turbojpeg-jni.c b/turbojpeg-jni.c
index 25cca7db..1ff9bbaf 100644
--- a/turbojpeg-jni.c
+++ b/turbojpeg-jni.c
@@ -635,7 +635,8 @@ JNIEXPORT jintArray JNICALL Java_org_libjpegturbo_turbojpeg_TJTransformer_transf
 		if(t[i].r.w!=0) w=t[i].r.w;
 		if(t[i].r.h!=0) h=t[i].r.h;
 		bailif0(jdstBufs[i]=(*env)->GetObjectArrayElement(env, dstobjs, i));
-		if((*env)->GetArrayLength(env, jdstBufs[i])<tjBufSize(w, h, jpegSubsamp))
+		if((unsigned long)(*env)->GetArrayLength(env, jdstBufs[i])
+			<tjBufSize(w, h, jpegSubsamp))
 			_throw("Destination buffer is not large enough");
 		bailif0(dstBufs[i]=(*env)->GetPrimitiveArrayCritical(env, jdstBufs[i], 0));
 	}
diff --git a/turbojpeg.c b/turbojpeg.c
index e27f0da0..2d5959a3 100644
--- a/turbojpeg.c
+++ b/turbojpeg.c
@@ -1065,7 +1065,7 @@ DLLEXPORT int DLLCALL tjTransform(tjhandle handle, unsigned char *jpegBuf,
 			&xinfo[i]);
 		if(t[i].customFilter)
 		{
-			int ci, by, y;
+			int ci, y;  JDIMENSION by;
 			for(ci=0; ci<cinfo->num_components; ci++)
 			{
 				jpeg_component_info *compptr=&cinfo->comp_info[ci];