diff --git a/src/tint/writer/glsl/generator_impl.cc b/src/tint/writer/glsl/generator_impl.cc
index 6bab928..f0ffc53 100644
--- a/src/tint/writer/glsl/generator_impl.cc
+++ b/src/tint/writer/glsl/generator_impl.cc
@@ -2717,7 +2717,11 @@
       out << "~";
       break;
     case ast::UnaryOp::kNot:
-      out << "!";
+      if (TypeOf(expr)->UnwrapRef()->is_scalar()) {
+        out << "!";
+      } else {
+        out << "not";
+      }
       break;
     case ast::UnaryOp::kNegation:
       out << "-";
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordEqual_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordEqual_Vector.spvasm.expected.glsl
index 795babe..88263df 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordEqual_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordEqual_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(notEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(notEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThanEqual_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThanEqual_Vector.spvasm.expected.glsl
index c56133f..52aee68 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThanEqual_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThanEqual_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(lessThan(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(lessThan(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThan_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThan_Vector.spvasm.expected.glsl
index f78d5be..f9b125c 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThan_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordGreaterThan_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(lessThanEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(lessThanEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThanEqual_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThanEqual_Vector.spvasm.expected.glsl
index cf5d832..12919de 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThanEqual_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThanEqual_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(greaterThan(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(greaterThan(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThan_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThan_Vector.spvasm.expected.glsl
index 8674bdd..065f4b7 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThan_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordLessThan_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(greaterThanEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(greaterThanEqual(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordNotEqual_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordNotEqual_Vector.spvasm.expected.glsl
index b435170..fdf860b 100644
--- a/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordNotEqual_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvFUnordTest_FUnordNotEqual_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(equal(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
+  bvec2 x_1 = not(equal(vec2(50.0f, 60.0f), vec2(60.0f, 50.0f)));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-
diff --git a/test/tint/unittest/reader/spirv/SpvUnaryLogicalTest_LogicalNot_Vector.spvasm.expected.glsl b/test/tint/unittest/reader/spirv/SpvUnaryLogicalTest_LogicalNot_Vector.spvasm.expected.glsl
index 01e2b29..158f14c 100644
--- a/test/tint/unittest/reader/spirv/SpvUnaryLogicalTest_LogicalNot_Vector.spvasm.expected.glsl
+++ b/test/tint/unittest/reader/spirv/SpvUnaryLogicalTest_LogicalNot_Vector.spvasm.expected.glsl
@@ -1,10 +1,8 @@
-SKIP: FAILED
-
 #version 310 es
 precision mediump float;
 
 void main_1() {
-  bvec2 x_1 = !(bvec2(true, false));
+  bvec2 x_1 = not(bvec2(true, false));
   return;
 }
 
@@ -16,10 +14,3 @@
   tint_symbol();
   return;
 }
-Error parsing GLSL shader:
-ERROR: 0:5: '!' :  wrong operand type no operation '!' exists that takes an operand of type  const 2-component vector of bool (or there is no acceptable conversion)
-ERROR: 0:5: '' : compilation terminated 
-ERROR: 2 compilation errors.  No code generated.
-
-
-