Index: clang/lib/AST/Interp/ByteCodeExprGen.h
===================================================================
--- clang/lib/AST/Interp/ByteCodeExprGen.h
+++ clang/lib/AST/Interp/ByteCodeExprGen.h
@@ -268,6 +268,14 @@
     return FPO.getRoundingMode();
   }
 
+  std::optional<PrimType> classifyComplexElementType(QualType T) const {
+    assert(T->isAnyComplexType());
+
+    QualType ElemType = T->getAs<ComplexType>()->getElementType();
+
+    return this->classify(ElemType);
+  }
+
   bool emitRecordDestruction(const Descriptor *Desc);
   bool emitDerivedToBaseCasts(const RecordType *DerivedType,
                               const RecordType *BaseType, const Expr *E);
Index: clang/lib/AST/Interp/ByteCodeExprGen.cpp
===================================================================
--- clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -204,6 +204,52 @@
     return this->emitCast(*FromT, *ToT, CE);
   }
 
+  case CK_IntegralComplexToBoolean: {
+    std::optional<PrimType> ElemT =
+        classifyComplexElementType(SubExpr->getType());
+    if (!ElemT)
+      return false;
+    // We emit the expression (__real(E) != 0 || __imag(E) != 0)
+    // for us, that means (bool)E[0] || (bool)E[1]
+    if (!this->visit(SubExpr))
+      return false;
+    if (!this->emitConstUint8(0, CE))
+      return false;
+    if (!this->emitArrayElemPtrUint8(CE))
+      return false;
+    if (!this->emitLoadPop(*ElemT, CE))
+      return false;
+    if (!this->emitCast(*ElemT, PT_Bool, CE))
+      return false;
+    // We now have the bool value of E[0] on the stack.
+    LabelTy LabelTrue = this->getLabel();
+    if (!this->jumpTrue(LabelTrue))
+      return false;
+
+    if (!this->emitConstUint8(1, CE))
+      return false;
+    if (!this->emitArrayElemPtrPopUint8(CE))
+      return false;
+    if (!this->emitLoadPop(*ElemT, CE))
+      return false;
+    if (!this->emitCast(*ElemT, PT_Bool, CE))
+      return false;
+    // Leave the boolean value of E[1] on the stack.
+    LabelTy EndLabel = this->getLabel();
+    this->jump(EndLabel);
+
+    this->emitLabel(LabelTrue);
+    if (!this->emitPopPtr(CE))
+      return false;
+    if (!this->emitConstBool(true, CE))
+      return false;
+
+    this->fallthrough(EndLabel);
+    this->emitLabel(EndLabel);
+
+    return true;
+  }
+
   case CK_ToVoid:
     return discard(SubExpr);
 
@@ -1114,6 +1160,9 @@
     return Indirect(*T);
   }
 
+  if (LV->getType()->isAnyComplexType())
+    return visit(LV);
+
   return false;
 }
 
Index: clang/test/AST/Interp/complex.cpp
===================================================================
--- clang/test/AST/Interp/complex.cpp
+++ clang/test/AST/Interp/complex.cpp
@@ -49,8 +49,21 @@
 static_assert(__imag(I3) == 15, "");
 #endif
 
-
-
-
 /// FIXME: This should work in the new interpreter as well.
 // constexpr _Complex _BitInt(8) A = 0;// = {4};
+
+namespace CastToBool {
+  constexpr _Complex int F = {0, 1};
+  static_assert(F, "");
+  constexpr _Complex int F2 = {1, 0};
+  static_assert(F2, "");
+  constexpr _Complex int F3 = {0, 0};
+  static_assert(!F3, "");
+
+  constexpr _Complex unsigned char F4 = {0, 1};
+  static_assert(F4, "");
+  constexpr _Complex unsigned char F5 = {1, 0};
+  static_assert(F5, "");
+  constexpr _Complex unsigned char F6 = {0, 0};
+  static_assert(!F6, "");
+}