diff --git a/include/PR/gbi.h b/include/PR/gbi.h
index 46f888de4..d8fd26bf8 100644
--- a/include/PR/gbi.h
+++ b/include/PR/gbi.h
@@ -1049,7 +1049,12 @@ typedef struct {
  * First 8 words are integer portion of the 4x4 matrix
  * Last 8 words are the fraction portion of the 4x4 matrix
  */
+#ifdef GBI_FLOATS
+// 4x4 float matrix
+typedef float Mtx_t[4][4];
+#else
 typedef long Mtx_t[4][4];
+#endif
 
 typedef union {
 	Mtx_t         m;
diff --git a/src/lib/mtx_c.c b/src/lib/mtx_c.c
index b00044819..de3bcb975 100644
--- a/src/lib/mtx_c.c
+++ b/src/lib/mtx_c.c
@@ -366,6 +366,8 @@ void mtxF2L(Mtxf *src, Mtxf *dst)
 	dst->l[3][2] = src30 << 16 | (src31 & 0xffff);
 	dst->l[3][3] = src32 << 16 | (src33 & 0xffff);
 #else
-	bcopy(src, dst, sizeof(*dst));
+	if (src != dst) {
+		bcopy(src, dst, sizeof(*dst));
+	}
 #endif
 }
diff --git a/src/lib/ultra/gu/mtxutil.c b/src/lib/ultra/gu/mtxutil.c
index 1b3199fea..b461eee03 100644
--- a/src/lib/ultra/gu/mtxutil.c
+++ b/src/lib/ultra/gu/mtxutil.c
@@ -2,6 +2,11 @@
 
 void guMtxF2L(f32 mf[4][4], Mtx *m)
 {
+#ifdef GBI_FLOATS
+	if ((Mtx *)mf != m) {
+		bcopy(mf, m, sizeof(*m));
+	}
+#else
 	int	i, j;
 	int	e1, e2;
 	int	*ai, *af;
@@ -18,6 +23,7 @@ void guMtxF2L(f32 mf[4][4], Mtx *m)
 			*(af++) = ((e1 << 16) & 0xffff0000) | (e2 & 0xffff);
 		}
 	}
+#endif
 }
 
 void guMtxIdentF(float mf[4][4])