diff --git a/Resources/Shaders/oolite-default-planet.vertex b/Resources/Shaders/oolite-default-planet.vertex
index 8a7e4507..88873431 100644
--- a/Resources/Shaders/oolite-default-planet.vertex
+++ b/Resources/Shaders/oolite-default-planet.vertex
@@ -22,7 +22,7 @@
 */
 
 // No vNormal, because normal is always 0,0,1 in tangent space.
-uniform mat4			ooliteNormalMatrix;
+uniform mat3			ooliteNormalMatrix;
 uniform mat4			ooliteModelView;
 uniform mat4			ooliteModelViewProjection;
 uniform mat4			ooliteProjection;
@@ -37,8 +37,8 @@ void main(void)
 	vCoords = gl_Vertex.xyz;
 	
 	// Build tangent basis.
-	vec3 normal = normalize(mat3(ooliteNormalMatrix) * gl_Normal);
-	vec3 binormal = normalize(cross(normal, mat3(ooliteNormalMatrix) * vec3(0, 1, 0)));
+	vec3 normal = normalize(ooliteNormalMatrix * gl_Normal);
+	vec3 binormal = cross(normal, ooliteNormalMatrix * vec3(0, 1, 0));
 	vec3 tangent = -cross(normal, binormal);
 	
 	mat3 TBN = mat3(tangent, binormal, normal);
diff --git a/src/Core/Materials/OOShaderProgram.m b/src/Core/Materials/OOShaderProgram.m
index cb45d272..6d9046ff 100644
--- a/src/Core/Materials/OOShaderProgram.m
+++ b/src/Core/Materials/OOShaderProgram.m
@@ -414,7 +414,14 @@ static BOOL ValidateShaderObject(GLhandleARB object, NSString *name)
 			if ([obj isKindOfClass:[NSArray class]])
 			{
 				pair = (NSArray*)obj;
-				GLUniformMatrix([[pair objectAtIndex: 0] intValue], [matrixManager getMatrix: [[pair objectAtIndex: 1] intValue]]);
+				if ([[pair oo_stringAtIndex: 2] compare: @"mat3"] == 0)
+				{
+					GLUniformMatrix3([pair oo_intAtIndex: 0], [matrixManager getMatrix: [pair oo_intAtIndex: 1]]);
+				}
+				else
+				{
+					GLUniformMatrix([pair oo_intAtIndex: 0], [matrixManager getMatrix: [pair oo_intAtIndex: 1]]);
+				}
 			}
 		}
 	}
diff --git a/src/Core/OOMatrix.h b/src/Core/OOMatrix.h
index 0e6d0908..f0901f76 100644
--- a/src/Core/OOMatrix.h
+++ b/src/Core/OOMatrix.h
@@ -106,6 +106,7 @@ OOMatrix OOMatrixOrthogonalize(OOMatrix m) CONST_FUNC;
 #define GLMultTransposeOOMatrix(M) do { OOMatrix m_ = M; OOGL(glMultTransposeMatrixf(OOMatrixValuesForOpenGL(m_))); } while (0)
 #define GLLoadTransposeOOMatrix(M) do { OOMatrix m_ = M; OOGL(glLoadTransposeMatrixf(OOMatrixValuesForOpenGL(m_))); } while (0)
 #define GLUniformMatrix(location, M) do { OOGL(glUniformMatrix4fvARB(location, 1, NO, OOMatrixValuesForOpenGL(M))); } while (0)
+void GLUniformMatrix3(GLint location, OOMatrix M);
 
 OOINLINE OOMatrix OOMatrixLoadGLMatrix(GLenum matrixID) ALWAYS_INLINE_FUNC;
 #endif
@@ -135,14 +136,16 @@ void OOMatrixColumnOperation(OOMatrix *M, int column1, OOScalar factor1, int col
 
 // Transforms between square matrices
 
-// return matrix X such that XA = B, or zero matrix if X doesn't exist
+// return matrix X such that XA = B, or zero matrix if X doesn't exist.
 OOMatrix OOMatrixLeftTransform(OOMatrix A, OOMatrix B);
-// return matrix X such that AX = B, or zero matrix if X doesn't exist
+// return matrix X such that AX = B, or zero matrix if X doesn't exist.
 OOMatrix OOMatrixRightTransform(OOMatrix A, OOMatrix B);
 
 // Matrix inversion
 
 OOMatrix OOMatrixInverse(OOMatrix M);
+// Inverts matrix returning determinant of inverse in 
+OOMatrix OOMatrixInverseWithDeterminant(OOMatrix M, OOScalar *determinant);
 
 /*** Only inline definitions beyond this point ***/
 
diff --git a/src/Core/OOMatrix.m b/src/Core/OOMatrix.m
index 608cb834..afbad6df 100644
--- a/src/Core/OOMatrix.m
+++ b/src/Core/OOMatrix.m
@@ -393,3 +393,77 @@ OOMatrix OOMatrixInverse(OOMatrix M)
 	return OOMatrixLeftTransform(M, kIdentityMatrix);
 }
 
+OOMatrix OOMatrixInverseWithDeterminant(OOMatrix M, OOScalar *d)
+{
+	int i, j;
+	OOMatrix B = kIdentityMatrix;
+	BOOL found;
+
+	*d = 1.0;
+	for (i = 0; i < 4; i++)
+	{
+		if (M.m[i][i] == 0.0)
+		{
+			found = NO;
+			for (j = i+1; j < 4; j++)
+			{
+				if (M.m[j][i] != 0.0)
+				{
+					found = YES;
+					OOMatrixRowSwap(&M,i,j);
+					OOMatrixRowSwap(&B,i,j);
+					*d *= -1;
+					break;
+				}
+			}
+			if (!found)
+			{
+				*d = 0.0;
+				return kZeroMatrix;
+			}
+		}
+		*d /= M.m[i][i];
+		OOMatrixRowScale(&B, i, 1/M.m[i][i]);
+		OOMatrixRowScale(&M, i, 1/M.m[i][i]);
+		for (j = i+1; j < 4; j++)
+		{
+			if (M.m[j][i] != 0.0)
+			{
+				OOMatrixRowOperation(&B, j, 1, i, -M.m[j][i]);
+				OOMatrixRowOperation(&M, j, 1, i, -M.m[j][i]);
+			}
+		}
+	}
+	for (i = 3; i > 0; i--)
+	{
+		for (j = 0; j < i; j++)
+		{
+			if (M.m[j][i] != 0.0)
+			{
+				OOMatrixRowOperation(&B, j, 1, i, -M.m[j][i]);
+				OOMatrixRowOperation(&M, j, 1, i, -M.m[j][i]);
+			}
+		}
+	}
+	return B;
+}
+
+#if OOMATHS_OPENGL_INTEGRATION
+
+void GLUniformMatrix3(int location, OOMatrix M)
+{
+	OOScalar m[9];
+	m[0] = M.m[0][0];
+	m[1] = M.m[0][1];
+	m[2] = M.m[0][2];
+	m[3] = M.m[1][0];
+	m[4] = M.m[1][1];
+	m[5] = M.m[1][2];
+	m[6] = M.m[2][0];
+	m[7] = M.m[2][1];
+	m[8] = M.m[2][2];
+	OOGL(glUniformMatrix3fvARB(location, 1, NO, m));
+}
+
+#endif
+
diff --git a/src/Core/OOOpenGLMatrixManager.m b/src/Core/OOOpenGLMatrixManager.m
index f4a36d0d..37c9e740 100644
--- a/src/Core/OOOpenGLMatrixManager.m
+++ b/src/Core/OOOpenGLMatrixManager.m
@@ -351,6 +351,7 @@ static OOOpenGLMatrixManager * sharedMatrixManager = nil;
 {
 	if (which < 0 || which >= OOLITE_GL_MATRIX_END) return kIdentityMatrix;
 	if (valid[which]) return matrices[which];
+	OOScalar d;
 	switch(which)
 	{
 	case OOLITE_GL_MATRIX_MODELVIEW_PROJECTION:
@@ -365,7 +366,18 @@ static OOOpenGLMatrixManager * sharedMatrixManager = nil;
 		matrices[which].m[1][3] = 0.0;
 		matrices[which].m[2][3] = 0.0;
 		matrices[which].m[3][3] = 1.0;
-		matrices[which] = OOMatrixTranspose(OOMatrixInverse(matrices[which]));
+		matrices[which] = OOMatrixTranspose(OOMatrixInverseWithDeterminant(matrices[which], &d));
+		if (d != 0.0)
+		{
+			d = pow(fabs(d), 1.0/3);
+			for (int i = 0; i < 3; i++)
+			{
+				for (int j = 0; j < 3; j++)
+				{
+					matrices[which].m[i][j] /= d;
+				}
+			}
+		}
 		break;
 	case OOLITE_GL_MATRIX_MODELVIEW_INVERSE:
 		matrices[which] = OOMatrixInverse(matrices[OOLITE_GL_MATRIX_MODELVIEW]);
@@ -402,17 +414,30 @@ static OOOpenGLMatrixManager * sharedMatrixManager = nil;
 - (NSArray*) standardMatrixUniformLocations: (GLuint) program
 {
 	GLint location;
-	int i;
+	NSUInteger i;
 	NSMutableArray *locationSet = [[[NSMutableArray alloc] init] autorelease];
 	
 	for (i = 0; i < OOLITE_GL_MATRIX_END; i++) {
 		location = glGetUniformLocationARB(program, ooliteStandardMatrixUniforms[i]);
 		if (location >= 0) {
-			[locationSet addObject:
-				[NSArray arrayWithObjects:
-					[NSNumber numberWithInt: location],
-					[NSNumber numberWithInt: i],
-					nil]];
+			if (i == OOLITE_GL_MATRIX_NORMAL)
+			{
+				[locationSet addObject:
+					[NSArray arrayWithObjects:
+						[NSNumber numberWithInt: location],
+						[NSNumber numberWithInt: i],
+						@"mat3",
+						nil]];
+			}
+			else
+			{
+				[locationSet addObject:
+					[NSArray arrayWithObjects:
+						[NSNumber numberWithInt: location],
+						[NSNumber numberWithInt: i],
+						@"mat4",
+						nil]];
+			}
 		}
 	}
 	return [[NSArray arrayWithArray: locationSet] retain];