diff --git a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
index 04469f1933819..8ebe8d54b041c 100644
--- a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
+++ b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.cpp
@@ -2158,6 +2158,53 @@ LogicalResult spirv::Deserializer::wireUpBlockArgument() {
   return success();
 }
 
+LogicalResult spirv::Deserializer::splitConditionalBlocks() {
+  // Create a copy, so we can modify keys in the original.
+  BlockMergeInfoMap blockMergeInfoCopy = blockMergeInfo;
+  for (auto it = blockMergeInfoCopy.begin(), e = blockMergeInfoCopy.end();
+       it != e; ++it) {
+    auto &[block, mergeInfo] = *it;
+
+    // Skip processing loop regions. For loop regions continueBlock is non-null.
+    if (mergeInfo.continueBlock)
+      continue;
+
+    if (!block->mightHaveTerminator())
+      continue;
+
+    Operation *terminator = block->getTerminator();
+    assert(terminator);
+
+    if (!isa<spirv::BranchConditionalOp>(terminator))
+      continue;
+
+    // Do not split blocks that only contain a conditional branch, i.e., block
+    // size is <= 1.
+    if (block->begin() != block->end() &&
+        std::next(block->begin()) != block->end()) {
+      Block *newBlock = block->splitBlock(terminator);
+      OpBuilder builder(block, block->end());
+      builder.create<spirv::BranchOp>(block->getParent()->getLoc(), newBlock);
+
+      // If the split block was a merge block of another region we need to
+      // update the map.
+      for (auto it = blockMergeInfo.begin(); it != blockMergeInfo.end(); ++it) {
+        auto &[ignore, mergeInfo] = *it;
+        if (mergeInfo.mergeBlock == block) {
+          mergeInfo.mergeBlock = newBlock;
+        }
+      }
+
+      // After splitting we need to update the map to use the new block as a
+      // header.
+      blockMergeInfo.erase(block);
+      blockMergeInfo.try_emplace(newBlock, mergeInfo);
+    }
+  }
+
+  return success();
+}
+
 LogicalResult spirv::Deserializer::structurizeControlFlow() {
   LLVM_DEBUG({
     logger.startLine()
@@ -2165,6 +2212,18 @@ LogicalResult spirv::Deserializer::structurizeControlFlow() {
     logger.indent();
   });
 
+  LLVM_DEBUG({
+    logger.startLine() << "[cf] split conditional blocks\n";
+    logger.startLine() << "\n";
+  });
+
+  if (failed(splitConditionalBlocks())) {
+    return failure();
+  }
+
+  // TODO: This loop is non-deterministic. Iteration order may vary between runs
+  // for the same shader as the key to the map is a pointer. See:
+  // https://github.com/llvm/llvm-project/issues/128547
   while (!blockMergeInfo.empty()) {
     Block *headerBlock = blockMergeInfo.begin()->first;
     BlockMergeInfo mergeInfo = blockMergeInfo.begin()->second;
diff --git a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
index 264d580c40f09..8dd35aa876726 100644
--- a/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
+++ b/mlir/lib/Target/SPIRV/Deserialization/Deserializer.h
@@ -246,6 +246,10 @@ class Deserializer {
     return opBuilder.getStringAttr(attrName);
   }
 
+  // Move a conditional branch into a separate basic block to avoid sinking
+  // defs that are required outside a selection region.
+  LogicalResult splitConditionalBlocks();
+
   //===--------------------------------------------------------------------===//
   // Type
   //===--------------------------------------------------------------------===//
diff --git a/mlir/test/Target/SPIRV/selection.mlir b/mlir/test/Target/SPIRV/selection.mlir
index f1d35d74dba15..24abb12998d06 100644
--- a/mlir/test/Target/SPIRV/selection.mlir
+++ b/mlir/test/Target/SPIRV/selection.mlir
@@ -105,6 +105,8 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %var = spirv.Variable : !spirv.ptr<i1, Function>
 // CHECK-NEXT:    spirv.Branch ^[[BB:.+]]
 // CHECK-NEXT:  ^[[BB]]:
+// CHECK:    spirv.Branch ^[[BB:.+]]
+// CHECK-NEXT:  ^[[BB]]:
 
 // CHECK-NEXT:    spirv.mlir.selection {
     spirv.mlir.selection {
diff --git a/mlir/test/Target/SPIRV/selection.spv b/mlir/test/Target/SPIRV/selection.spv
new file mode 100644
index 0000000000000..9642d0a44fb59
--- /dev/null
+++ b/mlir/test/Target/SPIRV/selection.spv
@@ -0,0 +1,60 @@
+; RUN: %if spirv-tools %{ spirv-as --target-env spv1.0 %s -o - | mlir-translate --deserialize-spirv - -o - | FileCheck %s %}
+
+; COM: The purpose of this test is to check that a variable (in this case %color) that
+; COM: is defined before a selection region and used both in the selection region and
+; COM: after it, is not sunk into that selection region by the deserializer. If the
+; COM: variable is sunk, then it cannot be accessed outside the region and causes
+; COM: control-flow structurization to fail.
+
+; CHECK:      spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
+; CHECK:        spirv.func @main() "None" {
+; CHECK:          spirv.Variable : !spirv.ptr<vector<4xf32>, Function>
+; CHECK:          spirv.mlir.selection {
+; CHECK-NEXT:       spirv.BranchConditional {{.*}}, ^[[bb:.+]], ^[[bb:.+]]
+; CHECK-NEXT:     ^[[bb:.+]]
+; CHECK:            spirv.Branch ^[[bb:.+]]
+; CHECK-NEXT:     ^[[bb:.+]]:
+; CHECK-NEXT:       spirv.mlir.merge
+; CHECK-NEXT:     }
+; CHECK:          spirv.Return
+; CHECK-NEXT:   }
+; CHECK:      }
+
+               OpCapability Shader
+          %2 = OpExtInstImport "GLSL.std.450"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %colorOut
+               OpExecutionMode %main OriginUpperLeft
+               OpDecorate %colorOut Location 0
+       %void = OpTypeVoid
+          %4 = OpTypeFunction %void
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%fun_v4float = OpTypePointer Function %v4float
+    %float_1 = OpConstant %float 1
+    %float_0 = OpConstant %float 0
+         %13 = OpConstantComposite %v4float %float_1 %float_0 %float_0 %float_1
+%out_v4float = OpTypePointer Output %v4float
+   %colorOut = OpVariable %out_v4float Output   
+       %uint = OpTypeInt 32 0
+     %uint_0 = OpConstant %uint 0
+  %out_float = OpTypePointer Output %float
+       %bool = OpTypeBool
+         %25 = OpConstantComposite %v4float %float_1 %float_1 %float_0 %float_1
+       %main = OpFunction %void None %4
+          %6 = OpLabel
+      %color = OpVariable %fun_v4float Function
+               OpStore %color %13
+         %19 = OpAccessChain %out_float %colorOut %uint_0
+         %20 = OpLoad %float %19
+         %22 = OpFOrdEqual %bool %20 %float_1
+               OpSelectionMerge %24 None
+               OpBranchConditional %22 %23 %24
+         %23 = OpLabel
+               OpStore %color %25
+               OpBranch %24
+         %24 = OpLabel
+         %26 = OpLoad %v4float %color
+               OpStore %colorOut %26
+               OpReturn
+               OpFunctionEnd
diff --git a/mlir/test/lit.cfg.py b/mlir/test/lit.cfg.py
index 32b2f8b53d5fa..8578c76969e74 100644
--- a/mlir/test/lit.cfg.py
+++ b/mlir/test/lit.cfg.py
@@ -43,6 +43,7 @@
     ".test",
     ".pdll",
     ".c",
+    ".spv",
 ]
 
 # test_source_root: The root path where tests are located.