diff --git a/include/sigar_private.h b/include/sigar_private.h
index 2159f676..e7b9e6fc 100644
--- a/include/sigar_private.h
+++ b/include/sigar_private.h
@@ -87,7 +87,7 @@ int sigar_os_open(sigar_t **sigar);
 
 int sigar_os_close(sigar_t *sigar);
 
-char *sigar_os_error_string(int err);
+char *sigar_os_error_string(sigar_t *sigar, int err);
 
 int sigar_proc_list_create(sigar_proc_list_t *proclist);
 
diff --git a/src/os/aix/aix_sigar.c b/src/os/aix/aix_sigar.c
index cf4a56a6..59395219 100644
--- a/src/os/aix/aix_sigar.c
+++ b/src/os/aix/aix_sigar.c
@@ -191,7 +191,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     switch (err) {
       case SIGAR_EPERM_KMEM:
diff --git a/src/os/darwin/darwin_sigar.c b/src/os/darwin/darwin_sigar.c
index 8f30ec3a..574f88d9 100644
--- a/src/os/darwin/darwin_sigar.c
+++ b/src/os/darwin/darwin_sigar.c
@@ -186,7 +186,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     switch (err) {
       case SIGAR_EPERM_KMEM:
diff --git a/src/os/hpux/hpux_sigar.c b/src/os/hpux/hpux_sigar.c
index 38aa6b2c..404ef0cf 100644
--- a/src/os/hpux/hpux_sigar.c
+++ b/src/os/hpux/hpux_sigar.c
@@ -41,7 +41,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     return NULL;
 }
diff --git a/src/os/linux/linux_sigar.c b/src/os/linux/linux_sigar.c
index 937a70d1..93cd69bc 100644
--- a/src/os/linux/linux_sigar.c
+++ b/src/os/linux/linux_sigar.c
@@ -153,7 +153,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     return NULL;
 }
diff --git a/src/os/osf1/osf1_sigar.c b/src/os/osf1/osf1_sigar.c
index b554d27f..74f52e65 100644
--- a/src/os/osf1/osf1_sigar.c
+++ b/src/os/osf1/osf1_sigar.c
@@ -29,7 +29,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     return NULL;
 }
diff --git a/src/os/solaris/solaris_sigar.c b/src/os/solaris/solaris_sigar.c
index 722adf5e..0bb3a441 100644
--- a/src/os/solaris/solaris_sigar.c
+++ b/src/os/solaris/solaris_sigar.c
@@ -143,7 +143,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     return NULL;
 }
diff --git a/src/os/stub/stub_sigar.c b/src/os/stub/stub_sigar.c
index 0dfe648a..96e170fa 100644
--- a/src/os/stub/stub_sigar.c
+++ b/src/os/stub/stub_sigar.c
@@ -16,7 +16,7 @@ int sigar_os_close(sigar_t *sigar)
     return SIGAR_OK;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     return NULL;
 }
diff --git a/src/os/win32/win32_sigar.c b/src/os/win32/win32_sigar.c
index 270d1388..63614ae1 100644
--- a/src/os/win32/win32_sigar.c
+++ b/src/os/win32/win32_sigar.c
@@ -266,7 +266,7 @@ int sigar_os_close(sigar_t *sigar)
     return retval;
 }
 
-char *sigar_os_error_string(int err)
+char *sigar_os_error_string(sigar_t *sigar, int err)
 {
     switch (err) {
       case SIGAR_NO_SUCH_PROCESS:
diff --git a/src/sigar.c b/src/sigar.c
index c5d0db82..dd8b5423 100644
--- a/src/sigar.c
+++ b/src/sigar.c
@@ -99,7 +99,7 @@ SIGAR_DECLARE(char *) sigar_strerror(sigar_t *sigar, int err)
 #endif
 
     if (err > SIGAR_OS_START_ERROR) {
-        if ((buf = sigar_os_error_string(err)) != NULL) {
+        if ((buf = sigar_os_error_string(sigar, err)) != NULL) {
             return buf;
         }
         return "Unknown OS Error"; /* should never happen */