diff --git a/src/Nemo.jl b/src/Nemo.jl
index 148957ee8..0a400004c 100644
--- a/src/Nemo.jl
+++ b/src/Nemo.jl
@@ -107,7 +107,7 @@ end
 # check whether we are using flint version >= 3.0 (or some recent enough dev version),
 # which changed the layout of some structs
 _ptr = Libc.dlopen(libflint)
-if Libc.dlsym(_ptr, :_fmpz_mod_vec_set_fmpz_vec_threaded; throw_error = false) != nothing
+if Libc.dlsym(_ptr, :_fmpz_mod_vec_set_fmpz_vec_threaded; throw_error = false) !== nothing
   const NEW_FLINT = true
 	libantic = libflint
 	libarb = libflint
diff --git a/src/calcium/CalciumTypes.jl b/src/calcium/CalciumTypes.jl
index d2e52f462..8e38a183e 100644
--- a/src/calcium/CalciumTypes.jl
+++ b/src/calcium/CalciumTypes.jl
@@ -149,7 +149,7 @@ mutable struct CalciumField <: Field
 
       for (opt, value) in options
          i = findfirst(isequal(opt), ca_ctx_options)
-         (i == nothing) && error("unknown option ", opt)
+         (i === nothing) && error("unknown option ", opt)
          ccall((:ca_ctx_set_option, libcalcium), Nothing, (Ref{CalciumField}, Int, Int), C, i - 1, value)
       end
 
diff --git a/src/embedding/embedding.jl b/src/embedding/embedding.jl
index cb052af29..5a7b41d5e 100644
--- a/src/embedding/embedding.jl
+++ b/src/embedding/embedding.jl
@@ -385,7 +385,7 @@ function embed(k::T, K::T) where T <: FinField
     # If k is already embedded in K, we return the corresponding embedding
 
     tr = is_embedded(k, K)
-    if tr != nothing
+    if tr !== nothing
         return tr
     end
 
@@ -395,7 +395,7 @@ function embed(k::T, K::T) where T <: FinField
 
     if degree(k) == degree(K)
         tr = is_embedded(K, k)
-        if tr != nothing
+        if tr !== nothing
             return preimage_map(tr)
         end
     end