diff --git a/index.js b/index.js
index 9711418..4b6dbb1 100644
--- a/index.js
+++ b/index.js
@@ -42,6 +42,10 @@ function minifier(safe_words, mutate_storages) {
     if(node.parent && is_redundant_vector_literal(node.parent) && node.parent.children.indexOf(node) > 1) return
     if(is_redundant_vector_literal(node)) node.children = node.children.slice(0, 2)
 
+    // mat2(1.0, 0.0, 0.0, 1.0) => mat2(1.0)
+    if(node.parent && is_redundant_matrix_literal(node.parent) && node.parent.children.indexOf(node) > 1) return
+    if(is_redundant_matrix_literal(node)) node.children = node.children.slice(0, 2)
+
     if(should_mutate(node)) {
       var t = node.parent.parent.children[1]
       if(mutate_storages || (t.type === 'placeholder' || t.token.data === 'const')) {
@@ -91,4 +95,28 @@ function minifier(safe_words, mutate_storages) {
     }
     return false
   }
+
+  function is_redundant_matrix_literal(node) {
+    if(node.type === 'call' && /^mat[234]$/.test(node.children[0].data) &&
+      (node.children[1].type === 'literal' || node.children[1].type === 'ident')) {
+      var rows = Math.sqrt(node.children.length - 1);
+      var first = node.children[1].data;
+
+      for(var i = 2; i < node.children.length; i++) {
+        var diagonalPosition = !((i - 1) % (rows + 1));
+        var data = node.children[i].data;
+
+        if (diagonalPosition) {
+          if (data !== first) {
+            return false;
+          }
+        } else if (!(node.children[i].type === 'literal' || node.children[i].type === 'ident') || parseFloat(data) !== 0) {
+          return false;
+        }
+      }
+
+      return true
+    }
+    return false
+  }
 }
diff --git a/tap-snapshots/test-basic.js-TAP.test.js b/tap-snapshots/test-basic.js-TAP.test.js
index 3272e44..b32e7f1 100644
--- a/tap-snapshots/test-basic.js-TAP.test.js
+++ b/tap-snapshots/test-basic.js-TAP.test.js
@@ -744,6 +744,25 @@ bool c = 1. && true && true;
 bool d = 0. || false || true;
 `
 
+exports[`test/basic.js TAP mat shorthand > output 1`] = `
+
+mat2 mat2Long = mat2(1., 1., 1., 1.);
+mat2 mat2Short = mat2(1.);
+mat3 mat3Long = mat3(1., 1., 1., 1., 1., 1., 1., 1., 1.);
+mat3 mat3Short = mat3(1.);
+mat4 mat4Long = mat4(1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1.);
+mat4 mat4Short = mat4(1.);
+mat2 a = mat2(1., .0, .0, .0);
+float b = 1.;
+float c = .0;
+mat2 d = mat2(b, c, c, b);
+vec3 e = vec3(1, 0, 0);
+vec3 f = vec3(0, 1, 0);
+vec3 g = vec3(0, 0, 1);
+mat3 h = mat3(e, f, g);
+mat3 i = mat3(mat3(1));
+`
+
 exports[`test/basic.js TAP vec shorthand > output 1`] = `
 
 vec2 vec2Long = vec2(.0, 1.);
diff --git a/test/basic.js b/test/basic.js
index 63da188..6ec591e 100644
--- a/test/basic.js
+++ b/test/basic.js
@@ -12,6 +12,7 @@ const zeroGLSL = path.resolve(__dirname, "./zero-decimals.glsl");
 const commutativeGLSL = path.resolve(__dirname, "./commutative-operators.glsl");
 const workingGLSL = path.resolve(__dirname, "./working.glsl");
 const vecGLSL = path.resolve(__dirname, "./vec-shorthand.glsl");
+const matGLSL = path.resolve(__dirname, "./mat-shorthand.glsl");
 
 tap.test("basic", t => {
 	let output = "";
@@ -157,3 +158,47 @@ tap.test("grouping removal test", t => {
 	.pipe(endStream);
 });
 
+tap.test("mat shorthand", t => {
+	const types = [2,3,4].map(size => `mat${size}`);
+
+	const variableNames = types
+	.map(type => ["Short", "Long"].map(suffix => `${type}${suffix}`))
+	.reduce((a, b) => a.concat(b));
+
+	const safewords = [
+		"main",
+		...variableNames,
+	];
+
+	let output = "";
+
+	const endStream = through((data) => {
+		output += data;
+	}, () => {
+		t.matchSnapshot(output, "output");
+
+		t.ok(
+			variableNames
+			.filter(name => name.endsWith("Long"))
+			.every(name => output.includes(`${name} = ${name.replace("Long", "")}(1., 1.`)),
+			"does not retain differing scalars"
+		);
+
+		t.ok(
+			variableNames
+			.filter(name => name.endsWith("Short"))
+			.every(name => output.includes(`${name} = ${name.replace("Short", "")}(1.)`)),
+			"does not shorten identical scalars"
+		);
+
+		t.end();
+	});
+
+	fs.createReadStream(matGLSL)
+	.pipe(tokenizer())
+	.pipe(parser())
+	.pipe(minify(safewords))
+	.pipe(deparser())
+	.pipe(endStream);
+});
+
diff --git a/test/mat-shorthand.glsl b/test/mat-shorthand.glsl
new file mode 100644
index 0000000..5f6db4f
--- /dev/null
+++ b/test/mat-shorthand.glsl
@@ -0,0 +1,62 @@
+mat2 mat2Long = mat2(
+	1.0, 1.0,
+	1.0, 1.0
+);
+
+mat2 mat2Short = mat2(
+	1.0, 0.0,
+	0.0, 1.0
+);
+
+mat3 mat3Long = mat3(
+	1.0, 1.0, 1.0,
+	1.0, 1.0, 1.0,
+	1.0, 1.0, 1.0
+);
+
+mat3 mat3Short = mat3(
+	1.0, 0.0, 0.0,
+	0.0, 1.0, 0.0,
+	0.0, 0.0, 1.0
+);
+
+
+mat4 mat4Long = mat4(
+	1.0, 1.0, 1.0, 1.0,
+	1.0, 1.0, 1.0, 1.0,
+	1.0, 1.0, 1.0, 1.0,
+	1.0, 1.0, 1.0, 1.0
+);
+
+mat4 mat4Short = mat4(
+	1.0, 0.0, 0.0, 0.0,
+	0.0, 1.0, 0.0, 0.0,
+	0.0, 0.0, 1.0, 0.0,
+	0.0, 0.0, 0.0, 1.0
+);
+
+mat2 mat2NotQuiteShort = mat2(
+	1.0, 0.0,
+	0.0, 0.0
+);
+
+float one = 1.0;
+float zero = 0.0;
+
+mat2 mat2WithIdentShort = mat2(
+	one, zero,
+	zero, one
+);
+
+vec3 vec3one = vec3(1,0,0);
+vec3 vec3two = vec3(0,1,0);
+vec3 vec3three = vec3(0,0,1);
+
+mat3 mat3WithVecIdent = mat3(
+  vec3one,
+  vec3two,
+  vec3three
+);
+
+mat3 mat3WithMat = mat3(mat3(1, 0, 0, 0, 1, 0, 0, 0, 1));
+