diff --git a/flang/docs/Extensions.md b/flang/docs/Extensions.md
index fbeada77d6443..cf6b65c0a6f5e 100644
--- a/flang/docs/Extensions.md
+++ b/flang/docs/Extensions.md
@@ -99,6 +99,7 @@ end
 * `<>` as synonym for `.NE.` and `/=`
 * `$` and `@` as legal characters in names
 * Initialization in type declaration statements using `/values/`
+* Saved integer, logical and real scalars are zero initialized.
 * Kind specification with `*`, e.g. `REAL*4`
 * `DOUBLE COMPLEX` as a synonym for `COMPLEX(KIND(0.D0))` --
   but not when spelled `TYPE(DOUBLECOMPLEX)`.
diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index 65ae694d23f66..c0343356a84af 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -495,7 +495,9 @@ static fir::GlobalOp defineGlobal(Fortran::lower::AbstractConverter &converter,
   } else {
     TODO(loc, "global"); // Procedure pointer or something else
   }
-  // Creates undefined initializer for globals without initializers
+  // Creates zero or undefined initializer for globals without initializers
+  // Zero initializer is used for "simple types" (integer, real and logical),
+  // undefined is used for types aside from those types.
   if (!globalIsInitialized(global)) {
     // TODO: Is it really required to add the undef init if the Public
     // visibility is set ? We need to make sure the global is not optimized out
@@ -507,8 +509,12 @@ static fir::GlobalOp defineGlobal(Fortran::lower::AbstractConverter &converter,
       TODO(loc, "BIND(C) module variable linkage");
     Fortran::lower::createGlobalInitialization(
         builder, global, [&](fir::FirOpBuilder &builder) {
-          builder.create<fir::HasValueOp>(
-              loc, builder.create<fir::UndefOp>(loc, symTy));
+          mlir::Value initValue;
+          if (symTy.isa<mlir::IntegerType, mlir::FloatType, fir::LogicalType>())
+            initValue = builder.create<fir::ZeroOp>(loc, symTy);
+          else
+            initValue = builder.create<fir::UndefOp>(loc, symTy);
+          builder.create<fir::HasValueOp>(loc, initValue);
         });
   }
   // Set public visibility to prevent global definition to be optimized out
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index 72f02cb425299..c96ce573e9c4d 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -3283,7 +3283,7 @@ struct ZeroOpConversion : public FIROpConversion<fir::ZeroOp> {
       rewriter.replaceOpWithNewOp<mlir::LLVM::NullOp>(zero, ty);
     } else if (ty.isa<mlir::IntegerType>()) {
       rewriter.replaceOpWithNewOp<mlir::LLVM::ConstantOp>(
-          zero, ty, mlir::IntegerAttr::get(zero.getType(), 0));
+          zero, ty, mlir::IntegerAttr::get(ty, 0));
     } else if (mlir::LLVM::isCompatibleFloatingPointType(ty)) {
       rewriter.replaceOpWithNewOp<mlir::LLVM::ConstantOp>(
           zero, ty, mlir::FloatAttr::get(zero.getType(), 0.0));
diff --git a/flang/test/Lower/target_definition.f90 b/flang/test/Lower/target_definition.f90
index 2bde8b31c4a1d..88b31e4598d43 100644
--- a/flang/test/Lower/target_definition.f90
+++ b/flang/test/Lower/target_definition.f90
@@ -2,7 +2,7 @@
 
 ! Test TARGET attributes on a definition of a global symbol.
 ! CHECK: fir.global @_QMtarget_modEx target : f32 {
-! CHECK:   %[[init:.*]] = fir.undefined f32
+! CHECK:   %[[init:.*]] = fir.zero_bits f32
 ! CHECK:   fir.has_value %[[init]] : f32
 ! CHECK: }