diff --git a/tools/seismic_3D-tools/m_stdio.f90 b/tools/seismic_3D-tools/m_stdio.f90
index bddb715..bc00f68 100644
--- a/tools/seismic_3D-tools/m_stdio.f90
+++ b/tools/seismic_3D-tools/m_stdio.f90
@@ -65,8 +65,6 @@ module stdio
   real(PN), parameter :: DEG2RAD = PI/180._PN
   real(PN), parameter :: RAD2DEG = 180.0_PN / PI
 
-  integer, external :: iargc
-
 
   interface readPrm
   !