diff --git a/src/cmd/compile/internal/ssa/fuse.go b/src/cmd/compile/internal/ssa/fuse.go
index a530874b80..c2d4051da8 100644
--- a/src/cmd/compile/internal/ssa/fuse.go
+++ b/src/cmd/compile/internal/ssa/fuse.go
@@ -145,7 +145,7 @@ func fuseBlockIf(b *Block) bool {
 // There may be false positives.
 func isEmpty(b *Block) bool {
 	for _, v := range b.Values {
-		if v.Uses > 0 || v.Type.IsVoid() {
+		if v.Uses > 0 || v.Op.IsCall() || v.Op.HasSideEffects() || v.Type.IsVoid() {
 			return false
 		}
 	}
diff --git a/src/cmd/compile/internal/ssa/fuse_test.go b/src/cmd/compile/internal/ssa/fuse_test.go
index c3e25a80c4..77d2aad5c1 100644
--- a/src/cmd/compile/internal/ssa/fuse_test.go
+++ b/src/cmd/compile/internal/ssa/fuse_test.go
@@ -63,7 +63,7 @@ func TestFuseEliminatesBothBranches(t *testing.T) {
 			t.Errorf("then was not eliminated, but should have")
 		}
 		if b == fun.blocks["else"] && b.Kind != BlockInvalid {
-			t.Errorf("then was not eliminated, but should have")
+			t.Errorf("else was not eliminated, but should have")
 		}
 	}
 }
@@ -97,7 +97,7 @@ func TestFuseHandlesPhis(t *testing.T) {
 			t.Errorf("then was not eliminated, but should have")
 		}
 		if b == fun.blocks["else"] && b.Kind != BlockInvalid {
-			t.Errorf("then was not eliminated, but should have")
+			t.Errorf("else was not eliminated, but should have")
 		}
 	}
 }
@@ -131,6 +131,40 @@ func TestFuseEliminatesEmptyBlocks(t *testing.T) {
 	}
 }
 
+func TestFuseSideEffects(t *testing.T) {
+	// Test that we don't fuse branches that have side effects but
+	// have no use (e.g. followed by infinite loop).
+	// See issue #36005.
+	c := testConfig(t)
+	fun := c.Fun("entry",
+		Bloc("entry",
+			Valu("mem", OpInitMem, types.TypeMem, 0, nil),
+			Valu("b", OpArg, c.config.Types.Bool, 0, nil),
+			If("b", "then", "else")),
+		Bloc("then",
+			Valu("call1", OpStaticCall, types.TypeMem, 0, nil, "mem"),
+			Goto("empty")),
+		Bloc("else",
+			Valu("call2", OpStaticCall, types.TypeMem, 0, nil, "mem"),
+			Goto("empty")),
+		Bloc("empty",
+			Goto("loop")),
+		Bloc("loop",
+			Goto("loop")))
+
+	CheckFunc(fun.f)
+	fuseAll(fun.f)
+
+	for _, b := range fun.f.Blocks {
+		if b == fun.blocks["then"] && b.Kind == BlockInvalid {
+			t.Errorf("then is eliminated, but should not")
+		}
+		if b == fun.blocks["else"] && b.Kind == BlockInvalid {
+			t.Errorf("else is eliminated, but should not")
+		}
+	}
+}
+
 func BenchmarkFuse(b *testing.B) {
 	for _, n := range [...]int{1, 10, 100, 1000, 10000} {
 		b.Run(strconv.Itoa(n), func(b *testing.B) {
diff --git a/src/cmd/compile/internal/ssa/gen/main.go b/src/cmd/compile/internal/ssa/gen/main.go
index 2107da4f4e..8520c68a5a 100644
--- a/src/cmd/compile/internal/ssa/gen/main.go
+++ b/src/cmd/compile/internal/ssa/gen/main.go
@@ -405,6 +405,7 @@ func genOp() {
 
 	fmt.Fprintln(w, "func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }")
 	fmt.Fprintln(w, "func (o Op) IsCall() bool { return opcodeTable[o].call }")
+	fmt.Fprintln(w, "func (o Op) HasSideEffects() bool { return opcodeTable[o].hasSideEffects }")
 	fmt.Fprintln(w, "func (o Op) UnsafePoint() bool { return opcodeTable[o].unsafePoint }")
 
 	// generate registers
diff --git a/src/cmd/compile/internal/ssa/opGen.go b/src/cmd/compile/internal/ssa/opGen.go
index a5951dd4e1..99dc60640c 100644
--- a/src/cmd/compile/internal/ssa/opGen.go
+++ b/src/cmd/compile/internal/ssa/opGen.go
@@ -31636,6 +31636,7 @@ func (o Op) String() string       { return opcodeTable[o].name }
 func (o Op) UsesScratch() bool    { return opcodeTable[o].usesScratch }
 func (o Op) SymEffect() SymEffect { return opcodeTable[o].symEffect }
 func (o Op) IsCall() bool         { return opcodeTable[o].call }
+func (o Op) HasSideEffects() bool { return opcodeTable[o].hasSideEffects }
 func (o Op) UnsafePoint() bool    { return opcodeTable[o].unsafePoint }
 
 var registers386 = [...]Register{