diff --git a/NEWS.md b/NEWS.md
index a1f5beb..ead7f6b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -122,7 +122,7 @@ Release of version 1.0.1
 - added `NLF2LF` transformation in postgresql `unifold` function
 - added the `DECOMPOSE` option, if you neither use `COMPOSE` or `DECOMPOSE`, no normalization will be performed (different from previous versions)
 - using integer constants rather than C-strings for character properties
-- fixed (hopefully) a problem with the ruby library on Mac OS X, which occured when compiler optimization was switched on
+- fixed (hopefully) a problem with the ruby library on Mac OS X, which occurred when compiler optimization was switched on
 
 ## Version 0.2 ##
 
diff --git a/mojibake.h b/mojibake.h
index d0f5b53..c47af66 100644
--- a/mojibake.h
+++ b/mojibake.h
@@ -102,7 +102,7 @@ extern "C" {
  *  Flags being regarded by several functions in the library:
  *  NULLTERM:  The given UTF-8 input is NULL terminated.
  *  STABLE:    Unicode Versioning Stability has to be respected.
- *  COMPAT:    Compatiblity decomposition
+ *  COMPAT:    Compatibility decomposition
  *             (i.e. formatting information is lost)
  *  COMPOSE:   Return a result with composed characters.
  *  DECOMPOSE: Return a result with decomposed characters.
diff --git a/utf8proc.c b/utf8proc.c
index 1064d4d..b907720 100644
--- a/utf8proc.c
+++ b/utf8proc.c
@@ -112,7 +112,7 @@ const char *utf8proc_errmsg(ssize_t errcode) {
     case UTF8PROC_ERROR_INVALIDOPTS:
     return "Invalid options for UTF-8 processing chosen.";
     default:
-    return "An unknown error occured while processing UTF-8 data.";
+    return "An unknown error occurred while processing UTF-8 data.";
   }
 }
 
@@ -370,7 +370,7 @@ ssize_t utf8proc_decompose(
     while (1) {
       if (options & UTF8PROC_NULLTERM) {
         rpos += utf8proc_iterate(str + rpos, -1, &uc);
-        /* checking of return value is not neccessary,
+        /* checking of return value is not necessary,
            as 'uc' is < 0 in case of error */
         if (uc < 0) return UTF8PROC_ERROR_INVALIDUTF8;
         if (rpos < 0) return UTF8PROC_ERROR_OVERFLOW;