diff --git a/cuda_core/cuda/core/_program.pyx b/cuda_core/cuda/core/_program.pyx
index 0b1fa93279..3188c73ecf 100644
--- a/cuda_core/cuda/core/_program.pyx
+++ b/cuda_core/cuda/core/_program.pyx
@@ -402,6 +402,31 @@ class ProgramOptions:
         # Set arch to default if not provided
         if self.arch is None:
             self.arch = f"sm_{Device().arch}"
+        if self.extra_sources is not None:
+            if not is_sequence(self.extra_sources):
+                raise TypeError(
+                    "extra_sources must be a sequence of 2-tuples: ((name1, source1), (name2, source2), ...)"
+                )
+            for i, module in enumerate(self.extra_sources):
+                if not isinstance(module, tuple) or len(module) != 2:
+                    raise TypeError(
+                        f"Each extra module must be a 2-tuple (name, source)"
+                        f", got {type(module).__name__} at index {i}"
+                    )
+
+                module_name, module_source = module
+
+                if not isinstance(module_name, str):
+                    raise TypeError(f"Module name at index {i} must be a string, got {type(module_name).__name__}")
+
+                if not isinstance(module_source, (str, bytes, bytearray)):
+                    raise TypeError(
+                        f"Module source at index {i} must be str (textual LLVM IR), bytes (textual LLVM IR or bitcode), "
+                        f"or bytearray, got {type(module_source).__name__}"
+                    )
+
+                if len(module_source) == 0:
+                    raise ValueError(f"Module source for '{module_name}' (index {i}) cannot be empty")
 
     def _prepare_nvrtc_options(self) -> list[bytes]:
         return _prepare_nvrtc_options_impl(self)
@@ -455,6 +480,23 @@ class ProgramOptions:
     def __repr__(self):
         return f"ProgramOptions(name={self.name!r}, arch={self.arch!r})"
 
+    def _prepare_extra_sources_bytes(self) -> list[tuple[bytes, bytes]] | None:
+        """Convert extra_sources to bytes format for NVVM."""
+        if self.extra_sources is None:
+            return None
+
+        result = []
+        for module_name, module_source in self.extra_sources:
+            name_bytes = module_name.encode("utf-8")
+            if isinstance(module_source, str):
+                source_bytes = module_source.encode("utf-8")
+            elif isinstance(module_source, bytearray):
+                source_bytes = bytes(module_source)
+            else:
+                source_bytes = module_source
+            result.append((name_bytes, source_bytes))
+        return result
+
 
 # =============================================================================
 # Private Classes and Helper Functions
@@ -624,41 +666,11 @@ cdef inline int Program_init(Program self, object code, str code_type, object op
 
         # Add extra modules if provided
         if options.extra_sources is not None:
-            if not is_sequence(options.extra_sources):
-                raise TypeError(
-                    "extra_sources must be a sequence of 2-tuples: ((name1, source1), (name2, source2), ...)"
-                )
-            for i, module in enumerate(options.extra_sources):
-                if not isinstance(module, tuple) or len(module) != 2:
-                    raise TypeError(
-                        f"Each extra module must be a 2-tuple (name, source)"
-                        f", got {type(module).__name__} at index {i}"
-                    )
-
-                module_name, module_source = module
-
-                if not isinstance(module_name, str):
-                    raise TypeError(f"Module name at index {i} must be a string, got {type(module_name).__name__}")
-
-                if isinstance(module_source, str):
-                    # Textual LLVM IR - encode to UTF-8 bytes
-                    module_source = module_source.encode("utf-8")
-                elif not isinstance(module_source, (bytes, bytearray)):
-                    raise TypeError(
-                        f"Module source at index {i} must be str (textual LLVM IR), bytes (textual LLVM IR or bitcode), "
-                        f"or bytearray, got {type(module_source).__name__}"
-                    )
-
-                if len(module_source) == 0:
-                    raise ValueError(f"Module source for '{module_name}' (index {i}) cannot be empty")
-
-                # Add the module using NVVM API
-                module_bytes = module_source if isinstance(module_source, bytes) else bytes(module_source)
+            extra_sources_bytes = options._prepare_extra_sources_bytes()
+            for module_name_bytes, module_bytes in extra_sources_bytes:
                 module_ptr = <const char*>module_bytes
                 module_len = len(module_bytes)
-                module_name_bytes = module_name.encode()
                 module_name_ptr = <const char*>module_name_bytes
-
                 with nogil:
                     HANDLE_RETURN_NVVM(nvvm_prog, cynvvm.nvvmAddModuleToProgram(
                         nvvm_prog, module_ptr, module_len, module_name_ptr))
diff --git a/cuda_core/tests/test_program.py b/cuda_core/tests/test_program.py
index 565305a1e3..d31bf607e0 100644
--- a/cuda_core/tests/test_program.py
+++ b/cuda_core/tests/test_program.py
@@ -697,7 +697,7 @@ def test_cpp_program_with_extra_sources():
     # negative test with NVRTC with multiple sources
     code = 'extern "C" __global__ void my_kernel(){}'
     helper = 'extern "C" __global__ void helper(){}'
-    options = ProgramOptions(extra_sources=helper)
+    options = ProgramOptions(extra_sources=[("helper", helper)])
     with pytest.raises(ValueError, match="extra_sources is not supported by the NVRTC backend"):
         Program(code, "c++", options)