diff --git a/colorm.go b/colorm.go
index 7dcbf3a1b..6e9ff8c6d 100644
--- a/colorm.go
+++ b/colorm.go
@@ -39,7 +39,8 @@ func (c *ColorM) Concat(other ColorM) {
 	c.impl.Concat(other.impl)
 }
 
-// Add adds a color matrix with the other color matrix.
+// Add is deprecated as of 1.5.0-alpha.
+// Note that this doesn't make sense in terms of additions two affine matrices.
 func (c *ColorM) Add(other ColorM) {
 	c.impl.Add(other.impl)
 }
diff --git a/colorm_test.go b/colorm_test.go
index 0f9b7e7d2..067c743d2 100644
--- a/colorm_test.go
+++ b/colorm_test.go
@@ -47,20 +47,6 @@ func TestColorInit(t *testing.T) {
 			}
 		}
 	}
-
-	m.Add(m)
-	for i := 0; i < ColorMDim-1; i++ {
-		for j := 0; j < ColorMDim; j++ {
-			got := m.Element(i, j)
-			want := 0.0
-			if i == j {
-				want = 2
-			}
-			if want != got {
-				t.Errorf("m.Element(%d, %d) = %f, want %f", i, j, got, want)
-			}
-		}
-	}
 }
 
 func TestColorAssign(t *testing.T) {
diff --git a/geom.go b/geom.go
index cfea42abb..4b1714fba 100644
--- a/geom.go
+++ b/geom.go
@@ -39,7 +39,8 @@ func (g *GeoM) Concat(other GeoM) {
 	g.impl.Concat(other.impl)
 }
 
-// Add adds a geometry matrix with the other geometry matrix.
+// Add is deprecated as of 1.5.0-alpha.
+// Note that this doesn't make sense in terms of additions two affine matrices.
 func (g *GeoM) Add(other GeoM) {
 	g.impl.Add(other.impl)
 }
diff --git a/geom_test.go b/geom_test.go
index bbb798fe5..984b5a001 100644
--- a/geom_test.go
+++ b/geom_test.go
@@ -33,20 +33,6 @@ func TestGeometryInit(t *testing.T) {
 			}
 		}
 	}
-
-	m.Add(m)
-	for i := 0; i < GeoMDim-1; i++ {
-		for j := 0; j < GeoMDim; j++ {
-			got := m.Element(i, j)
-			want := 0.0
-			if i == j {
-				want = 2
-			}
-			if want != got {
-				t.Errorf("m.Element(%d, %d) = %f, want %f", i, j, got, want)
-			}
-		}
-	}
 }
 
 func TestGeometryAssign(t *testing.T) {