diff --git a/libisofs/fs_image.c b/libisofs/fs_image.c
index e55ac7e..36c167a 100644
--- a/libisofs/fs_image.c
+++ b/libisofs/fs_image.c
@@ -364,7 +364,7 @@ typedef struct
      */
     int px_ino_status;
 
-    /* Which Rock Ridge error messages already have occured
+    /* Which Rock Ridge error messages already have occurred
        bit0= Invalid PX entry
        bit1= Invalid TF entry
        bit2= New NM entry found without previous CONTINUE flag
diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index c618e8e..2e74f71 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -2510,7 +2510,7 @@ int iso_interval_reader_destroy(struct iso_interval_reader **ivr, int flag);
  *        Pointer to memory for filling in at least 2048 bytes.
  * @param buf_fill
  *        Will in case of success return the number of valid bytes.
- *        If this is smaller than 2048, then end-of-interval has occured.
+ *        If this is smaller than 2048, then end-of-interval has occurred.
  * @param flag
  *        Unused yet. Submit 0.
  * @return
@@ -8791,16 +8791,16 @@ int iso_conv_name_chars(IsoWriteOpts *opts, char *name, size_t name_len,
 /* ! PLACE NEW ERROR CODES ABOVE. NOT AFTER THIS LINE ! */
 
 
-/** Read error occured with IsoDataSource (SORRY,HIGH, -513) */
+/** Read error occurred with IsoDataSource (SORRY,HIGH, -513) */
 #define ISO_DATA_SOURCE_SORRY     0xE030FCFF
 
-/** Read error occured with IsoDataSource (MISHAP,HIGH, -513) */
+/** Read error occurred with IsoDataSource (MISHAP,HIGH, -513) */
 #define ISO_DATA_SOURCE_MISHAP    0xE430FCFF
 
-/** Read error occured with IsoDataSource (FAILURE,HIGH, -513) */
+/** Read error occurred with IsoDataSource (FAILURE,HIGH, -513) */
 #define ISO_DATA_SOURCE_FAILURE   0xE830FCFF
 
-/** Read error occured with IsoDataSource (FATAL,HIGH, -513) */
+/** Read error occurred with IsoDataSource (FATAL,HIGH, -513) */
 #define ISO_DATA_SOURCE_FATAL     0xF030FCFF
 
 
diff --git a/libisofs/messages.c b/libisofs/messages.c
index 7d4d16e..c6fb194 100644
--- a/libisofs/messages.c
+++ b/libisofs/messages.c
@@ -380,7 +380,7 @@ const char *iso_error_to_msg(int errcode)
     case ISO_DATA_SOURCE_MISHAP:
     case ISO_DATA_SOURCE_FAILURE:
     case ISO_DATA_SOURCE_FATAL:
-        return "Read error occured with IsoDataSource";
+        return "Read error occurred with IsoDataSource";
     case ISO_AAIP_IGNORED:
         return "AAIP info with ACL or xattr in ISO image will be ignored";
     case ISO_AAIP_BAD_ACL: