diff --git a/doc/source/f2py/code/ftype.f b/doc/source/f2py/code/ftype.f
index cabbb9e2d5da..67d5a224b949 100644
--- a/doc/source/f2py/code/ftype.f
+++ b/doc/source/f2py/code/ftype.f
@@ -4,6 +4,6 @@ SUBROUTINE FOO(N)
 Cf2py integer optional,intent(in) :: n = 13
       REAL A,X
       COMMON /DATA/ A,X(3)
-      PRINT*, "IN FOO: N=",N," A=",A," X=[",X(1),X(2),X(3),"]"
+C     PRINT*, "IN FOO: N=",N," A=",A," X=[",X(1),X(2),X(3),"]"
       END
 C END OF FTYPE.F
diff --git a/numpy/f2py/crackfortran.py b/numpy/f2py/crackfortran.py
index 61e83d555385..c0a79bcae941 100755
--- a/numpy/f2py/crackfortran.py
+++ b/numpy/f2py/crackfortran.py
@@ -2856,6 +2856,11 @@ def compute_deps(v, deps):
                         kindselect, charselect, typename = cracktypespec(
                             typespec, selector)
                         vars[n]['typespec'] = typespec
+                        try:
+                            if block['result']:
+                                vars[block['result']]['typespec'] = typespec
+                        except Exception:
+                            pass
                         if kindselect:
                             if 'kind' in kindselect:
                                 try:
diff --git a/numpy/f2py/func2subr.py b/numpy/f2py/func2subr.py
index 2a05f065b625..cc3cdc5b4f90 100644
--- a/numpy/f2py/func2subr.py
+++ b/numpy/f2py/func2subr.py
@@ -119,6 +119,12 @@ def add(line, ret=ret):
 
     sargs = ', '.join(args)
     if f90mode:
+        # gh-23598 fix warning
+        # Essentially, this gets called again with modules where the name of the
+        # function is added to the arguments, which is not required, and removed
+        sargs = sargs.replace(f"{name}, ", '')
+        args = [arg for arg in args if arg != name]
+        rout['args'] = args
         add('subroutine f2pywrap_%s_%s (%s)' %
             (rout['modulename'], name, sargs))
         if not signature:
diff --git a/numpy/f2py/tests/src/crackfortran/gh23598.f90 b/numpy/f2py/tests/src/crackfortran/gh23598.f90
new file mode 100644
index 000000000000..e0dffb5ef29e
--- /dev/null
+++ b/numpy/f2py/tests/src/crackfortran/gh23598.f90
@@ -0,0 +1,4 @@
+integer function intproduct(a, b) result(res)
+  integer, intent(in) :: a, b
+  res = a*b
+end function
diff --git a/numpy/f2py/tests/src/crackfortran/gh23598Warn.f90 b/numpy/f2py/tests/src/crackfortran/gh23598Warn.f90
new file mode 100644
index 000000000000..3b44efc5ef16
--- /dev/null
+++ b/numpy/f2py/tests/src/crackfortran/gh23598Warn.f90
@@ -0,0 +1,11 @@
+module test_bug
+    implicit none
+    private
+    public :: intproduct
+
+contains
+    integer function intproduct(a, b) result(res)
+    integer, intent(in) :: a, b
+    res = a*b
+    end function
+end module
diff --git a/numpy/f2py/tests/test_crackfortran.py b/numpy/f2py/tests/test_crackfortran.py
index 39555df05b9f..dc0f7e27a9cb 100644
--- a/numpy/f2py/tests/test_crackfortran.py
+++ b/numpy/f2py/tests/test_crackfortran.py
@@ -312,4 +312,12 @@ def test_nameargspattern_backtracking(self, adversary):
             # according to the old version of the regex.
             # that should still be true.
             good_version_of_adversary = repeated_adversary + '@)@'
-            assert nameargspattern.search(good_version_of_adversary)
\ No newline at end of file
+            assert nameargspattern.search(good_version_of_adversary)
+
+
+class TestFunctionReturn(util.F2PyTest):
+    sources = [util.getpath("tests", "src", "crackfortran", "gh23598.f90")]
+
+    def test_function_rettype(self):
+        # gh-23598
+        assert self.module.intproduct(3, 4) == 12
diff --git a/numpy/f2py/tests/test_f2py2e.py b/numpy/f2py/tests/test_f2py2e.py
index 2c10f046f1d9..5f7b56a68a9d 100644
--- a/numpy/f2py/tests/test_f2py2e.py
+++ b/numpy/f2py/tests/test_f2py2e.py
@@ -62,6 +62,15 @@ def hello_world_f90(tmpdir_factory):
     return fn
 
 
+@pytest.fixture(scope="session")
+def gh23598_warn(tmpdir_factory):
+    """F90 file for testing warnings in gh23598"""
+    fdat = util.getpath("tests", "src", "crackfortran", "gh23598Warn.f90").read_text()
+    fn = tmpdir_factory.getbasetemp() / "gh23598Warn.f90"
+    fn.write_text(fdat, encoding="ascii")
+    return fn
+
+
 @pytest.fixture(scope="session")
 def hello_world_f77(tmpdir_factory):
     """Generates a single f77 file for testing"""
@@ -91,6 +100,19 @@ def f2cmap_f90(tmpdir_factory):
     return fn
 
 
+def test_gh23598_warn(capfd, gh23598_warn, monkeypatch):
+    foutl = get_io_paths(gh23598_warn, mname="test")
+    ipath = foutl.f90inp
+    monkeypatch.setattr(
+        sys, "argv",
+        f'f2py {ipath} -m test'.split())
+
+    with util.switchdir(ipath.parent):
+        f2pycli()  # Generate files
+        wrapper = foutl.wrap90.read_text()
+        assert "intproductf2pywrap, intpr" not in wrapper
+
+
 def test_gen_pyf(capfd, hello_world_f90, monkeypatch):
     """Ensures that a signature file is generated via the CLI
     CLI :: -h