diff --git a/common/OLD_uipriv.h b/common/OLD_uipriv.h
index 29583b0c..95ab829c 100644
--- a/common/OLD_uipriv.h
+++ b/common/OLD_uipriv.h
@@ -1,8 +1,3 @@
 
-// matrix.c
-extern void fallbackSkew(uiDrawMatrix *, double, double, double, double);
-extern void scaleCenter(double, double, double *, double *);
-extern void fallbackTransformSize(uiDrawMatrix *, double *, double *);
-
 // OS-specific text.* files
 extern int uiprivStricmp(const char *a, const char *b);
diff --git a/common/matrix.c b/common/matrix.c
index 676885d1..93d4d357 100644
--- a/common/matrix.c
+++ b/common/matrix.c
@@ -18,7 +18,7 @@ void uiDrawMatrixSetIdentity(uiDrawMatrix *m)
 
 // see https://msdn.microsoft.com/en-us/library/windows/desktop/ff684171%28v=vs.85%29.aspx#skew_transform
 // TODO see if there's a way we can avoid the multiplication
-void fallbackSkew(uiDrawMatrix *m, double x, double y, double xamount, double yamount)
+void uiprivFallbackSkew(uiDrawMatrix *m, double x, double y, double xamount, double yamount)
 {
 	uiDrawMatrix n;
 
@@ -31,7 +31,7 @@ void fallbackSkew(uiDrawMatrix *m, double x, double y, double xamount, double ya
 	uiDrawMatrixMultiply(m, &n);
 }
 
-void scaleCenter(double xCenter, double yCenter, double *x, double *y)
+void uiprivScaleCenter(double xCenter, double yCenter, double *x, double *y)
 {
 	*x = xCenter - (*x * xCenter);
 	*y = yCenter - (*y * yCenter);
@@ -39,7 +39,7 @@ void scaleCenter(double xCenter, double yCenter, double *x, double *y)
 
 // the basic algorithm is from cairo
 // but it's the same algorithm as the transform point, just without M31 and M32 taken into account, so let's just do that instead
-void fallbackTransformSize(uiDrawMatrix *m, double *x, double *y)
+void uiprivFallbackTransformSize(uiDrawMatrix *m, double *x, double *y)
 {
 	uiDrawMatrix m2;
 
diff --git a/common/uipriv.h b/common/uipriv.h
index 8fc3d42e..f9ad4c41 100644
--- a/common/uipriv.h
+++ b/common/uipriv.h
@@ -54,9 +54,9 @@ extern void uiprivClickCounterReset(uiprivClickCounter *);
 extern int uiprivFromScancode(uintptr_t, uiAreaKeyEvent *);
 
 // matrix.c
-extern void fallbackSkew(uiDrawMatrix *, double, double, double, double);
-extern void scaleCenter(double, double, double *, double *);
-extern void fallbackTransformSize(uiDrawMatrix *, double *, double *);
+extern void uiprivFallbackSkew(uiDrawMatrix *, double, double, double, double);
+extern void uiprivScaleCenter(double, double, double *, double *);
+extern void uiprivFallbackTransformSize(uiDrawMatrix *, double *, double *);
 
 // OS-specific text.* files
 extern int uiprivStricmp(const char *a, const char *b);
diff --git a/darwin/draw.m b/darwin/draw.m
index 7ca854d2..cf7d8f13 100644
--- a/darwin/draw.m
+++ b/darwin/draw.m
@@ -334,7 +334,7 @@ void uiDrawMatrixScale(uiDrawMatrix *m, double xCenter, double yCenter, double x
 	m2c(m, &c);
 	xt = x;
 	yt = y;
-	scaleCenter(xCenter, yCenter, &xt, &yt);
+	uiprivScaleCenter(xCenter, yCenter, &xt, &yt);
 	c = CGAffineTransformTranslate(c, xt, yt);
 	c = CGAffineTransformScale(c, x, y);
 	c = CGAffineTransformTranslate(c, -xt, -yt);
@@ -354,7 +354,7 @@ void uiDrawMatrixRotate(uiDrawMatrix *m, double x, double y, double amount)
 
 void uiDrawMatrixSkew(uiDrawMatrix *m, double x, double y, double xamount, double yamount)
 {
-	fallbackSkew(m, x, y, xamount, yamount);
+	uiprivFallbackSkew(m, x, y, xamount, yamount);
 }
 
 void uiDrawMatrixMultiply(uiDrawMatrix *dest, uiDrawMatrix *src)
diff --git a/unix/drawmatrix.c b/unix/drawmatrix.c
index ac7ac579..7d15d920 100644
--- a/unix/drawmatrix.c
+++ b/unix/drawmatrix.c
@@ -39,7 +39,7 @@ void uiDrawMatrixScale(uiDrawMatrix *m, double xCenter, double yCenter, double x
 	m2c(m, &c);
 	xt = x;
 	yt = y;
-	scaleCenter(xCenter, yCenter, &xt, &yt);
+	uiprivScaleCenter(xCenter, yCenter, &xt, &yt);
 	cairo_matrix_translate(&c, xt, yt);
 	cairo_matrix_scale(&c, x, y);
 	cairo_matrix_translate(&c, -xt, -yt);
@@ -59,7 +59,7 @@ void uiDrawMatrixRotate(uiDrawMatrix *m, double x, double y, double amount)
 
 void uiDrawMatrixSkew(uiDrawMatrix *m, double x, double y, double xamount, double yamount)
 {
-	fallbackSkew(m, x, y, xamount, yamount);
+	uiprivFallbackSkew(m, x, y, xamount, yamount);
 }
 
 void uiDrawMatrixMultiply(uiDrawMatrix *dest, uiDrawMatrix *src)
diff --git a/windows/drawmatrix.cpp b/windows/drawmatrix.cpp
index 090972a5..4ddc5e9a 100644
--- a/windows/drawmatrix.cpp
+++ b/windows/drawmatrix.cpp
@@ -113,5 +113,5 @@ void uiDrawMatrixTransformPoint(uiDrawMatrix *m, double *x, double *y)
 
 void uiDrawMatrixTransformSize(uiDrawMatrix *m, double *x, double *y)
 {
-	fallbackTransformSize(m, x, y);
+	uiprivFallbackTransformSize(m, x, y);
 }