diff --git a/atrip.org b/atrip.org
index 1fd7d91..2c14694 100644
--- a/atrip.org
+++ b/atrip.org
@@ -1863,6 +1863,9 @@ is mainly using the =DGEMM= function, which we declare as
 #+begin_src c++ :tangle (atrip-blas-h)
 #pragma once
 namespace atrip {
+
+  using Complex = std::complex<double>;
+
   extern "C" {
     void dgemm_(
       const char *transa,
@@ -1871,14 +1874,73 @@ namespace atrip {
       const int *n,
       const int *k,
       double *alpha,
-      const double *A,
+      const double *a,
       const int *lda,
-      const double *B,
+      const double *b,
       const int *ldb,
       double *beta,
-      double *C,
+      double *c,
       const int *ldc
     );
+
+    void zgemm_(
+      const char *transa,
+      const char *transb,
+      const int *m,
+      const int *n,
+      const int *k,
+      Complex *alpha,
+      const Complex *A,
+      const int *lda,
+      const Complex *B,
+      const int *ldb,
+      Complex *beta,
+      Complex *C,
+      const int *ldc
+    );
+  }
+
+
+  template <typename F=double>
+  void xgemm(const char *transa,
+             const char *transb,
+             const int *m,
+             const int *n,
+             const int *k,
+             F *alpha,
+             const F *A,
+             const int *lda,
+             const F *B,
+             const int *ldb,
+             F *beta,
+             F *C,
+             const int *ldc) {
+    dgemm_(transa, transb,
+           m, n, k,
+           alpha, A, lda,
+           B, ldb, beta,
+           C, ldc);
+  }
+
+  template <>
+  void xgemm(const char *transa,
+             const char *transb,
+             const int *m,
+             const int *n,
+             const int *k,
+             Complex *alpha,
+             const Complex *A,
+             const int *lda,
+             const Complex *B,
+             const int *ldb,
+             Complex *beta,
+             Complex *C,
+             const int *ldc) {
+    zgemm_(transa, transb,
+           m, n, k,
+           alpha, A, lda,
+           B, ldb, beta,
+           C, ldc);
   }
 }
 #+end_src